diff --git a/.ci/all.sh b/.ci/all.sh
new file mode 100755
index 0000000000..e8a7f272e4
--- /dev/null
+++ b/.ci/all.sh
@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+
+#
+# all.sh
+# Copyright (c) 2024 james@firefly-iii.org
+#
+# This file is part of Firefly III (https://github.com/firefly-iii).
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+#
+
+SCRIPT_DIR="$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
+
+$SCRIPT_DIR/phpcs.sh
+$SCRIPT_DIR/phpstan.sh
+$SCRIPT_DIR/phpmd.sh
diff --git a/app/Api/V1/Requests/Models/Account/StoreRequest.php b/app/Api/V1/Requests/Models/Account/StoreRequest.php
index 50a76d70e8..76049d4c14 100644
--- a/app/Api/V1/Requests/Models/Account/StoreRequest.php
+++ b/app/Api/V1/Requests/Models/Account/StoreRequest.php
@@ -26,6 +26,7 @@ namespace FireflyIII\Api\V1\Requests\Models\Account;
 
 use FireflyIII\Models\Location;
 use FireflyIII\Rules\IsBoolean;
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Rules\UniqueAccountNumber;
 use FireflyIII\Rules\UniqueIban;
 use FireflyIII\Support\Request\AppendsLocationData;
@@ -113,7 +114,7 @@ class StoreRequest extends FormRequest
             'credit_card_type'     => sprintf('nullable|in:%s|required_if:account_role,ccAsset', $ccPaymentTypes),
             'monthly_payment_date' => 'nullable|date|required_if:account_role,ccAsset|required_if:credit_card_type,monthlyFull',
             'liability_type'       => 'nullable|required_if:type,liability|required_if:type,liabilities|in:loan,debt,mortgage',
-            'liability_amount'     => 'required_with:liability_start_date|min:0|numeric|max:1000000000',
+            'liability_amount'     => ['required_with:liability_start_date', new IsValidPositiveAmount()],
             'liability_start_date' => 'required_with:liability_amount|date',
             'liability_direction'  => 'nullable|required_if:type,liability|required_if:type,liabilities|in:credit,debit',
             'interest'             => 'between:0,100|numeric',
diff --git a/app/Api/V1/Requests/Models/AvailableBudget/Request.php b/app/Api/V1/Requests/Models/AvailableBudget/Request.php
index e20e8513ac..5c653194e4 100644
--- a/app/Api/V1/Requests/Models/AvailableBudget/Request.php
+++ b/app/Api/V1/Requests/Models/AvailableBudget/Request.php
@@ -24,6 +24,7 @@ declare(strict_types=1);
 namespace FireflyIII\Api\V1\Requests\Models\AvailableBudget;
 
 use Carbon\Carbon;
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use Illuminate\Foundation\Http\FormRequest;
@@ -62,7 +63,7 @@ class Request extends FormRequest
         return [
             'currency_id'   => 'numeric|exists:transaction_currencies,id',
             'currency_code' => 'min:3|max:51|exists:transaction_currencies,code',
-            'amount'        => 'numeric|gt:0|max:1000000000',
+            'amount'        => ['nullable', new IsValidPositiveAmount()],
             'start'         => 'date',
             'end'           => 'date',
         ];
diff --git a/app/Api/V1/Requests/Models/Bill/StoreRequest.php b/app/Api/V1/Requests/Models/Bill/StoreRequest.php
index bc0ff0a208..a29f4106c8 100644
--- a/app/Api/V1/Requests/Models/Bill/StoreRequest.php
+++ b/app/Api/V1/Requests/Models/Bill/StoreRequest.php
@@ -25,6 +25,7 @@ declare(strict_types=1);
 namespace FireflyIII\Api\V1\Requests\Models\Bill;
 
 use FireflyIII\Rules\IsBoolean;
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use Illuminate\Foundation\Http\FormRequest;
@@ -72,8 +73,8 @@ class StoreRequest extends FormRequest
     {
         return [
             'name'           => 'between:1,255|uniqueObjectForUser:bills,name',
-            'amount_min'     => 'numeric|gt:0|required|max:1000000000',
-            'amount_max'     => 'numeric|gt:0|required|max:1000000000',
+            'amount_min'     => ['required', new IsValidPositiveAmount()],
+            'amount_max'     => ['required', new IsValidPositiveAmount()],
             'currency_id'    => 'numeric|exists:transaction_currencies,id',
             'currency_code'  => 'min:3|max:51|exists:transaction_currencies,code',
             'date'           => 'date|required',
diff --git a/app/Api/V1/Requests/Models/Bill/UpdateRequest.php b/app/Api/V1/Requests/Models/Bill/UpdateRequest.php
index 8965ff84d9..f5896eff17 100644
--- a/app/Api/V1/Requests/Models/Bill/UpdateRequest.php
+++ b/app/Api/V1/Requests/Models/Bill/UpdateRequest.php
@@ -26,6 +26,7 @@ namespace FireflyIII\Api\V1\Requests\Models\Bill;
 
 use FireflyIII\Models\Bill;
 use FireflyIII\Rules\IsBoolean;
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use Illuminate\Foundation\Http\FormRequest;
@@ -75,8 +76,8 @@ class UpdateRequest extends FormRequest
 
         return [
             'name'           => sprintf('between:1,255|uniqueObjectForUser:bills,name,%d', $bill->id),
-            'amount_min'     => 'numeric|gt:0|max:1000000000',
-            'amount_max'     => 'numeric|gt:0|max:1000000000',
+            'amount_min'     => ['nullable', new IsValidPositiveAmount()],
+            'amount_max'     => ['nullable', new IsValidPositiveAmount()],
             'currency_id'    => 'numeric|exists:transaction_currencies,id',
             'currency_code'  => 'min:3|max:51|exists:transaction_currencies,code',
             'date'           => 'date',
diff --git a/app/Api/V1/Requests/Models/Budget/StoreRequest.php b/app/Api/V1/Requests/Models/Budget/StoreRequest.php
index 62911d258b..2932342ddc 100644
--- a/app/Api/V1/Requests/Models/Budget/StoreRequest.php
+++ b/app/Api/V1/Requests/Models/Budget/StoreRequest.php
@@ -24,6 +24,7 @@ declare(strict_types=1);
 namespace FireflyIII\Api\V1\Requests\Models\Budget;
 
 use FireflyIII\Rules\IsBoolean;
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use FireflyIII\Validation\AutoBudget\ValidatesAutoBudgetRequest;
@@ -74,7 +75,7 @@ class StoreRequest extends FormRequest
             'notes'              => 'nullable|between:1,65536',
             // auto budget info
             'auto_budget_type'   => 'in:reset,rollover,adjusted,none',
-            'auto_budget_amount' => 'numeric|min:0|max:1000000000|required_if:auto_budget_type,reset|required_if:auto_budget_type,rollover|required_if:auto_budget_type,adjusted',
+            'auto_budget_amount' => ['required_if:auto_budget_type,reset', 'required_if:auto_budget_type,rollover', 'required_if:auto_budget_type,adjusted', new IsValidPositiveAmount()],
             'auto_budget_period' => 'in:daily,weekly,monthly,quarterly,half_year,yearly|required_if:auto_budget_type,reset|required_if:auto_budget_type,rollover|required_if:auto_budget_type,adjusted',
         ];
     }
diff --git a/app/Api/V1/Requests/Models/Budget/UpdateRequest.php b/app/Api/V1/Requests/Models/Budget/UpdateRequest.php
index 08c7680f17..fb520d6a16 100644
--- a/app/Api/V1/Requests/Models/Budget/UpdateRequest.php
+++ b/app/Api/V1/Requests/Models/Budget/UpdateRequest.php
@@ -25,6 +25,7 @@ namespace FireflyIII\Api\V1\Requests\Models\Budget;
 
 use FireflyIII\Models\Budget;
 use FireflyIII\Rules\IsBoolean;
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use FireflyIII\Validation\AutoBudget\ValidatesAutoBudgetRequest;
@@ -86,7 +87,7 @@ class UpdateRequest extends FormRequest
             'auto_budget_type'          => 'in:reset,rollover,adjusted,none',
             'auto_budget_currency_id'   => 'exists:transaction_currencies,id',
             'auto_budget_currency_code' => 'exists:transaction_currencies,code',
-            'auto_budget_amount'        => 'min:0|max:1000000000',
+            'auto_budget_amount'        => ['nullable', new IsValidPositiveAmount()],
             'auto_budget_period'        => 'in:daily,weekly,monthly,quarterly,half_year,yearly',
         ];
     }
diff --git a/app/Api/V1/Requests/Models/BudgetLimit/StoreRequest.php b/app/Api/V1/Requests/Models/BudgetLimit/StoreRequest.php
index 769648004a..a47e705ff8 100644
--- a/app/Api/V1/Requests/Models/BudgetLimit/StoreRequest.php
+++ b/app/Api/V1/Requests/Models/BudgetLimit/StoreRequest.php
@@ -23,6 +23,7 @@ declare(strict_types=1);
 
 namespace FireflyIII\Api\V1\Requests\Models\BudgetLimit;
 
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use Illuminate\Foundation\Http\FormRequest;
@@ -57,7 +58,7 @@ class StoreRequest extends FormRequest
         return [
             'start'         => 'required|before:end|date',
             'end'           => 'required|after:start|date',
-            'amount'        => 'required|gt:0|max:1000000000',
+            'amount'        => ['required', new IsValidPositiveAmount()],
             'currency_id'   => 'numeric|exists:transaction_currencies,id',
             'currency_code' => 'min:3|max:51|exists:transaction_currencies,code',
         ];
diff --git a/app/Api/V1/Requests/Models/BudgetLimit/UpdateRequest.php b/app/Api/V1/Requests/Models/BudgetLimit/UpdateRequest.php
index 637e884695..44921ac890 100644
--- a/app/Api/V1/Requests/Models/BudgetLimit/UpdateRequest.php
+++ b/app/Api/V1/Requests/Models/BudgetLimit/UpdateRequest.php
@@ -24,6 +24,7 @@ declare(strict_types=1);
 namespace FireflyIII\Api\V1\Requests\Models\BudgetLimit;
 
 use Carbon\Carbon;
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use Illuminate\Foundation\Http\FormRequest;
@@ -61,7 +62,7 @@ class UpdateRequest extends FormRequest
         return [
             'start'         => 'date',
             'end'           => 'date',
-            'amount'        => 'gt:0|max:1000000000',
+            'amount'        => ['nullable', new IsValidPositiveAmount()],
             'currency_id'   => 'numeric|exists:transaction_currencies,id',
             'currency_code' => 'min:3|max:51|exists:transaction_currencies,code',
         ];
diff --git a/app/Api/V1/Requests/Models/PiggyBank/StoreRequest.php b/app/Api/V1/Requests/Models/PiggyBank/StoreRequest.php
index f9125717a6..58aafada70 100644
--- a/app/Api/V1/Requests/Models/PiggyBank/StoreRequest.php
+++ b/app/Api/V1/Requests/Models/PiggyBank/StoreRequest.php
@@ -23,6 +23,7 @@ declare(strict_types=1);
 
 namespace FireflyIII\Api\V1\Requests\Models\PiggyBank;
 
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use Illuminate\Foundation\Http\FormRequest;
@@ -64,11 +65,11 @@ class StoreRequest extends FormRequest
     {
         return [
             'name'               => 'required|between:1,255|uniquePiggyBankForUser',
-            'current_amount'     => ['numeric', 'gte:0', 'lte:target_amount', 'max:1000000000'],
+            'current_amount'     => ['nullable', new IsValidPositiveAmount()],
             'account_id'         => 'required|numeric|belongsToUser:accounts,id',
             'object_group_id'    => 'numeric|belongsToUser:object_groups,id',
             'object_group_title' => 'between:1,255',
-            'target_amount'      => ['numeric', 'gte:0', 'lte:target_amount', 'required', 'max:1000000000'],
+            'target_amount'      => ['required', new IsValidPositiveAmount()],
             'start_date'         => 'date|nullable',
             'target_date'        => 'date|nullable|after:start_date',
             'notes'              => 'max:65000',
diff --git a/app/Api/V1/Requests/Models/PiggyBank/UpdateRequest.php b/app/Api/V1/Requests/Models/PiggyBank/UpdateRequest.php
index 8350906fc5..f2abb703cc 100644
--- a/app/Api/V1/Requests/Models/PiggyBank/UpdateRequest.php
+++ b/app/Api/V1/Requests/Models/PiggyBank/UpdateRequest.php
@@ -25,6 +25,7 @@ namespace FireflyIII\Api\V1\Requests\Models\PiggyBank;
 
 use FireflyIII\Models\PiggyBank;
 use FireflyIII\Rules\IsAssetAccountId;
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Rules\LessThanPiggyTarget;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
@@ -69,8 +70,8 @@ class UpdateRequest extends FormRequest
 
         return [
             'name'           => 'between:1,255|uniquePiggyBankForUser:'.$piggyBank->id,
-            'current_amount' => ['numeric', 'gte:0', new LessThanPiggyTarget(), 'max:1000000000'],
-            'target_amount'  => 'numeric|gte:0|max:1000000000',
+            'current_amount' => ['nullable', new LessThanPiggyTarget(), new IsValidPositiveAmount()],
+            'target_amount'  => ['nullable', new IsValidPositiveAmount()],
             'start_date'     => 'date|nullable',
             'target_date'    => 'date|nullable|after:start_date',
             'notes'          => 'max:65000',
diff --git a/app/Api/V1/Requests/Models/Recurrence/StoreRequest.php b/app/Api/V1/Requests/Models/Recurrence/StoreRequest.php
index 00cc6273ee..dfdec0eb6f 100644
--- a/app/Api/V1/Requests/Models/Recurrence/StoreRequest.php
+++ b/app/Api/V1/Requests/Models/Recurrence/StoreRequest.php
@@ -25,6 +25,7 @@ namespace FireflyIII\Api\V1\Requests\Models\Recurrence;
 
 use FireflyIII\Rules\BelongsUser;
 use FireflyIII\Rules\IsBoolean;
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use FireflyIII\Support\Request\GetRecurrenceData;
@@ -92,8 +93,8 @@ class StoreRequest extends FormRequest
             'repetitions.*.weekend'                => 'numeric|min:1|max:4',
 
             'transactions.*.description'           => 'required|between:1,255',
-            'transactions.*.amount'                => 'required|numeric|gt:0|max:1000000000',
-            'transactions.*.foreign_amount'        => 'nullable|numeric|gt:0|max:1000000000',
+            'transactions.*.amount'                => ['required', new IsValidPositiveAmount()],
+            'transactions.*.foreign_amount'        => ['nullable', new IsValidPositiveAmount()],
             'transactions.*.currency_id'           => 'nullable|numeric|exists:transaction_currencies,id',
             'transactions.*.currency_code'         => 'nullable|min:3|max:51|exists:transaction_currencies,code',
             'transactions.*.foreign_currency_id'   => 'nullable|numeric|exists:transaction_currencies,id',
diff --git a/app/Api/V1/Requests/Models/Recurrence/UpdateRequest.php b/app/Api/V1/Requests/Models/Recurrence/UpdateRequest.php
index 6efb5f0699..111f915303 100644
--- a/app/Api/V1/Requests/Models/Recurrence/UpdateRequest.php
+++ b/app/Api/V1/Requests/Models/Recurrence/UpdateRequest.php
@@ -26,6 +26,7 @@ namespace FireflyIII\Api\V1\Requests\Models\Recurrence;
 use FireflyIII\Models\Recurrence;
 use FireflyIII\Rules\BelongsUser;
 use FireflyIII\Rules\IsBoolean;
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use FireflyIII\Support\Request\GetRecurrenceData;
@@ -99,8 +100,8 @@ class UpdateRequest extends FormRequest
             'repetitions.*.weekend'                => 'nullable|numeric|min:1|max:4',
 
             'transactions.*.description'           => 'between:1,255',
-            'transactions.*.amount'                => 'numeric|gt:0|max:1000000000',
-            'transactions.*.foreign_amount'        => 'nullable|numeric|gt:0|max:1000000000',
+            'transactions.*.amount'                => [new IsValidPositiveAmount()],
+            'transactions.*.foreign_amount'        => ['nullable', new IsValidPositiveAmount()],
             'transactions.*.currency_id'           => 'nullable|numeric|exists:transaction_currencies,id',
             'transactions.*.currency_code'         => 'nullable|min:3|max:51|exists:transaction_currencies,code',
             'transactions.*.foreign_currency_id'   => 'nullable|numeric|exists:transaction_currencies,id',
@@ -164,15 +165,15 @@ class UpdateRequest extends FormRequest
             }
 
             if (array_key_exists('moment', $repetition)) {
-                $current['moment'] = (string)$repetition['moment'];
+                $current['moment'] = (string) $repetition['moment'];
             }
 
             if (array_key_exists('skip', $repetition)) {
-                $current['skip'] = (int)$repetition['skip'];
+                $current['skip'] = (int) $repetition['skip'];
             }
 
             if (array_key_exists('weekend', $repetition)) {
-                $current['weekend'] = (int)$repetition['weekend'];
+                $current['weekend'] = (int) $repetition['weekend'];
             }
             $return[] = $current;
         }
diff --git a/app/Api/V1/Requests/Models/Transaction/StoreRequest.php b/app/Api/V1/Requests/Models/Transaction/StoreRequest.php
index 0a5127aedc..aac847328a 100644
--- a/app/Api/V1/Requests/Models/Transaction/StoreRequest.php
+++ b/app/Api/V1/Requests/Models/Transaction/StoreRequest.php
@@ -27,6 +27,7 @@ namespace FireflyIII\Api\V1\Requests\Models\Transaction;
 use FireflyIII\Rules\BelongsUser;
 use FireflyIII\Rules\IsBoolean;
 use FireflyIII\Rules\IsDateOrTime;
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\NullArrayObject;
 use FireflyIII\Support\Request\AppendsLocationData;
 use FireflyIII\Support\Request\ChecksLogin;
@@ -92,8 +93,8 @@ class StoreRequest extends FormRequest
             'transactions.*.foreign_currency_code'   => 'min:3|max:51|exists:transaction_currencies,code|nullable',
 
             // amount
-            'transactions.*.amount'                  => 'required|numeric|gt:0|max:1000000000',
-            'transactions.*.foreign_amount'          => 'numeric|max:1000000000|gt:0|',
+            'transactions.*.amount'                  => ['required', new IsValidPositiveAmount()],
+            'transactions.*.foreign_amount'          => ['nullable', new IsValidPositiveAmount()],
 
             // description
             'transactions.*.description'             => 'nullable|between:1,1000',
diff --git a/app/Api/V1/Requests/Models/Transaction/UpdateRequest.php b/app/Api/V1/Requests/Models/Transaction/UpdateRequest.php
index 501534115f..201da4c38c 100644
--- a/app/Api/V1/Requests/Models/Transaction/UpdateRequest.php
+++ b/app/Api/V1/Requests/Models/Transaction/UpdateRequest.php
@@ -29,6 +29,7 @@ use FireflyIII\Models\TransactionGroup;
 use FireflyIII\Rules\BelongsUser;
 use FireflyIII\Rules\IsBoolean;
 use FireflyIII\Rules\IsDateOrTime;
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use FireflyIII\Validation\GroupValidation;
@@ -115,8 +116,8 @@ class UpdateRequest extends FormRequest
             'transactions.*.foreign_currency_code'   => 'nullable|min:3|max:51|exists:transaction_currencies,code',
 
             // amount
-            'transactions.*.amount'                  => 'numeric|gt:0|max:100000000000',
-            'transactions.*.foreign_amount'          => 'nullable|numeric|gte:0|max:1000000000',
+            'transactions.*.amount'                  => ['nullable', new IsValidPositiveAmount()],
+            'transactions.*.foreign_amount'          => ['nullable', new IsValidPositiveAmount()],
 
             // description
             'transactions.*.description'             => 'nullable|between:1,1000',
diff --git a/app/Http/Controllers/Controller.php b/app/Http/Controllers/Controller.php
index e5c7056abc..2c086c4057 100644
--- a/app/Http/Controllers/Controller.php
+++ b/app/Http/Controllers/Controller.php
@@ -28,9 +28,7 @@ use FireflyIII\Support\Http\Controllers\UserNavigation;
 use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
 use Illuminate\Foundation\Bus\DispatchesJobs;
 use Illuminate\Foundation\Validation\ValidatesRequests;
-use Illuminate\Http\UploadedFile;
 use Illuminate\Routing\Controller as BaseController;
-use Illuminate\Support\Facades\Log;
 
 /**
  * Class Controller.
diff --git a/app/Http/Requests/AccountFormRequest.php b/app/Http/Requests/AccountFormRequest.php
index 7095db6a26..7fb0f3755e 100644
--- a/app/Http/Requests/AccountFormRequest.php
+++ b/app/Http/Requests/AccountFormRequest.php
@@ -26,6 +26,7 @@ namespace FireflyIII\Http\Requests;
 use FireflyIII\Enums\UserRoleEnum;
 use FireflyIII\Models\Account;
 use FireflyIII\Models\Location;
+use FireflyIII\Rules\IsValidAmount;
 use FireflyIII\Rules\UniqueIban;
 use FireflyIII\Support\Request\AppendsLocationData;
 use FireflyIII\Support\Request\ChecksLogin;
@@ -101,11 +102,11 @@ class AccountFormRequest extends FormRequest
         $ccPaymentTypes = implode(',', array_keys(config('firefly.ccTypes')));
         $rules          = [
             'name'                               => 'required|max:1024|min:1|uniqueAccountForUser',
-            'opening_balance'                    => 'numeric|nullable|max:1000000000|min:-1000000000',
+            'opening_balance'                    => ['nullable', new IsValidAmount()],
             'opening_balance_date'               => 'date|required_with:opening_balance|nullable',
             'iban'                               => ['iban', 'nullable', new UniqueIban(null, $this->convertString('objectType'))],
             'BIC'                                => 'bic|nullable',
-            'virtual_balance'                    => 'numeric|nullable|max:1000000000|min:-1000000000',
+            'virtual_balance'                    => ['nullable', new IsValidAmount()],
             'currency_id'                        => 'exists:transaction_currencies,id',
             'account_number'                     => 'between:1,255|uniqueAccountNumberForUser|nullable',
             'account_role'                       => 'in:'.$accountRoles,
diff --git a/app/Http/Requests/BillStoreRequest.php b/app/Http/Requests/BillStoreRequest.php
index 9f46401736..c5fa73bf98 100644
--- a/app/Http/Requests/BillStoreRequest.php
+++ b/app/Http/Requests/BillStoreRequest.php
@@ -23,6 +23,7 @@ declare(strict_types=1);
 
 namespace FireflyIII\Http\Requests;
 
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use Illuminate\Foundation\Http\FormRequest;
@@ -64,8 +65,8 @@ class BillStoreRequest extends FormRequest
     {
         return [
             'name'                    => 'required|between:1,255|uniqueObjectForUser:bills,name',
-            'amount_min'              => 'required|numeric|gt:0|max:1000000000',
-            'amount_max'              => 'required|numeric|gt:0|max:1000000000',
+            'amount_min'              => ['required', new IsValidPositiveAmount()],
+            'amount_max'              => ['required', new IsValidPositiveAmount()],
             'transaction_currency_id' => 'required|exists:transaction_currencies,id',
             'date'                    => 'required|date',
             'notes'                   => 'between:1,65536|nullable',
diff --git a/app/Http/Requests/BillUpdateRequest.php b/app/Http/Requests/BillUpdateRequest.php
index c8189282ed..485cf0cc47 100644
--- a/app/Http/Requests/BillUpdateRequest.php
+++ b/app/Http/Requests/BillUpdateRequest.php
@@ -24,6 +24,7 @@ declare(strict_types=1);
 namespace FireflyIII\Http\Requests;
 
 use FireflyIII\Models\Bill;
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use Illuminate\Foundation\Http\FormRequest;
@@ -68,8 +69,8 @@ class BillUpdateRequest extends FormRequest
 
         return [
             'name'                    => sprintf('required|between:1,255|uniqueObjectForUser:bills,name,%d', $bill->id),
-            'amount_min'              => 'required|numeric|gt:0|max:1000000000',
-            'amount_max'              => 'required|numeric|gt:0|max:1000000000',
+            'amount_min'              => ['required', new IsValidPositiveAmount()],
+            'amount_max'              => ['required', new IsValidPositiveAmount()],
             'transaction_currency_id' => 'required|exists:transaction_currencies,id',
             'date'                    => 'required|date',
             'bill_end_date'           => 'nullable|date',
diff --git a/app/Http/Requests/BudgetFormStoreRequest.php b/app/Http/Requests/BudgetFormStoreRequest.php
index c50aeeaaf8..5200ff8544 100644
--- a/app/Http/Requests/BudgetFormStoreRequest.php
+++ b/app/Http/Requests/BudgetFormStoreRequest.php
@@ -23,6 +23,7 @@ declare(strict_types=1);
 
 namespace FireflyIII\Http\Requests;
 
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use FireflyIII\Validation\AutoBudget\ValidatesAutoBudgetRequest;
@@ -64,7 +65,7 @@ class BudgetFormStoreRequest extends FormRequest
             'active'                  => 'numeric|between:0,1',
             'auto_budget_type'        => 'numeric|integer|gte:0|lte:3',
             'auto_budget_currency_id' => 'exists:transaction_currencies,id',
-            'auto_budget_amount'      => 'min:0|max:1000000000|required_if:auto_budget_type,1|required_if:auto_budget_type,2',
+            'auto_budget_amount'      => ['required_if:auto_budget_type,1', 'required_if:auto_budget_type,2', new IsValidPositiveAmount()],
             'auto_budget_period'      => 'in:daily,weekly,monthly,quarterly,half_year,yearly',
             'notes'                   => 'between:1,65536|nullable',
         ];
diff --git a/app/Http/Requests/BudgetFormUpdateRequest.php b/app/Http/Requests/BudgetFormUpdateRequest.php
index 3c25e55306..486f614fe4 100644
--- a/app/Http/Requests/BudgetFormUpdateRequest.php
+++ b/app/Http/Requests/BudgetFormUpdateRequest.php
@@ -24,6 +24,7 @@ declare(strict_types=1);
 namespace FireflyIII\Http\Requests;
 
 use FireflyIII\Models\Budget;
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use FireflyIII\Validation\AutoBudget\ValidatesAutoBudgetRequest;
@@ -73,7 +74,7 @@ class BudgetFormUpdateRequest extends FormRequest
             'active'                  => 'numeric|between:0,1',
             'auto_budget_type'        => 'numeric|integer|gte:0|lte:31',
             'auto_budget_currency_id' => 'exists:transaction_currencies,id',
-            'auto_budget_amount'      => 'min:0|max:1000000000|required_if:auto_budget_type,1|required_if:auto_budget_type,2|numeric',
+            'auto_budget_amount'      => ['required_if:auto_budget_type,1', 'required_if:auto_budget_type,2|numeric', new IsValidPositiveAmount()],
             'auto_budget_period'      => 'in:daily,weekly,monthly,quarterly,half_year,yearly',
             'notes'                   => 'between:1,65536|nullable',
         ];
diff --git a/app/Http/Requests/BudgetIncomeRequest.php b/app/Http/Requests/BudgetIncomeRequest.php
index a89b818c3f..06575c0e19 100644
--- a/app/Http/Requests/BudgetIncomeRequest.php
+++ b/app/Http/Requests/BudgetIncomeRequest.php
@@ -23,6 +23,7 @@ declare(strict_types=1);
 
 namespace FireflyIII\Http\Requests;
 
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use Illuminate\Foundation\Http\FormRequest;
 
@@ -40,7 +41,7 @@ class BudgetIncomeRequest extends FormRequest
     {
         // fixed
         return [
-            'amount' => 'numeric|required|min:0|max:1000000000',
+            'amount' => ['required', new IsValidPositiveAmount()],
             'start'  => 'required|date|before:end',
             'end'    => 'required|date|after:start',
         ];
diff --git a/app/Http/Requests/NewUserFormRequest.php b/app/Http/Requests/NewUserFormRequest.php
index 2d4c3396b8..9955455972 100644
--- a/app/Http/Requests/NewUserFormRequest.php
+++ b/app/Http/Requests/NewUserFormRequest.php
@@ -23,6 +23,7 @@ declare(strict_types=1);
 
 namespace FireflyIII\Http\Requests;
 
+use FireflyIII\Rules\IsValidAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use Illuminate\Foundation\Http\FormRequest;
@@ -43,9 +44,9 @@ class NewUserFormRequest extends FormRequest
         // fixed
         return [
             'bank_name'                            => 'required|between:1,200',
-            'bank_balance'                         => 'required|numeric|max:1000000000|min:-1000000000',
-            'savings_balance'                      => 'numeric|max:1000000000|min:-1000000000',
-            'credit_card_limit'                    => 'numeric|max:1000000000|min:-1000000000',
+            'bank_balance'                         => ['required', new IsValidAmount()],
+            'savings_balance'                      => ['nullable', new IsValidAmount()],
+            'credit_card_limit'                    => ['nullable', new IsValidAmount()],
             'amount_currency_id_bank_balance'      => 'exists:transaction_currencies,id',
             'amount_currency_id_savings_balance'   => 'exists:transaction_currencies,id',
             'amount_currency_id_credit_card_limit' => 'exists:transaction_currencies,id',
diff --git a/app/Http/Requests/PiggyBankStoreRequest.php b/app/Http/Requests/PiggyBankStoreRequest.php
index 03be27f855..0892ae75bc 100644
--- a/app/Http/Requests/PiggyBankStoreRequest.php
+++ b/app/Http/Requests/PiggyBankStoreRequest.php
@@ -23,6 +23,7 @@ declare(strict_types=1);
 
 namespace FireflyIII\Http\Requests;
 
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use Illuminate\Foundation\Http\FormRequest;
@@ -59,7 +60,7 @@ class PiggyBankStoreRequest extends FormRequest
         return [
             'name'         => 'required|between:1,255|uniquePiggyBankForUser',
             'account_id'   => 'required|belongsToUser:accounts',
-            'targetamount' => 'nullable|numeric|max:1000000000|min:-1000000000',
+            'targetamount' => ['nullable', new IsValidPositiveAmount()],
             'startdate'    => 'date',
             'targetdate'   => 'date|nullable',
             'order'        => 'integer|min:1',
diff --git a/app/Http/Requests/PiggyBankUpdateRequest.php b/app/Http/Requests/PiggyBankUpdateRequest.php
index a67170dcc5..6b61cf084a 100644
--- a/app/Http/Requests/PiggyBankUpdateRequest.php
+++ b/app/Http/Requests/PiggyBankUpdateRequest.php
@@ -24,6 +24,7 @@ declare(strict_types=1);
 namespace FireflyIII\Http\Requests;
 
 use FireflyIII\Models\PiggyBank;
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
 use Illuminate\Foundation\Http\FormRequest;
@@ -63,7 +64,7 @@ class PiggyBankUpdateRequest extends FormRequest
         return [
             'name'         => sprintf('required|between:1,255|uniquePiggyBankForUser:%d', $piggy->id),
             'account_id'   => 'required|belongsToUser:accounts',
-            'targetamount' => 'nullable|numeric|max:1000000000|min:-1000000000',
+            'targetamount' => ['nullable', new IsValidPositiveAmount()],
             'startdate'    => 'date',
             'targetdate'   => 'date|nullable',
             'order'        => 'integer|max:65536|min:1',
diff --git a/app/Http/Requests/ReconciliationStoreRequest.php b/app/Http/Requests/ReconciliationStoreRequest.php
index f02bdb365a..4a73ca8ee8 100644
--- a/app/Http/Requests/ReconciliationStoreRequest.php
+++ b/app/Http/Requests/ReconciliationStoreRequest.php
@@ -23,6 +23,7 @@ declare(strict_types=1);
 
 namespace FireflyIII\Http\Requests;
 
+use FireflyIII\Rules\IsValidAmount;
 use FireflyIII\Rules\ValidJournals;
 use FireflyIII\Support\Request\ChecksLogin;
 use FireflyIII\Support\Request\ConvertsDataTypes;
@@ -67,9 +68,9 @@ class ReconciliationStoreRequest extends FormRequest
         return [
             'start'        => 'required|date',
             'end'          => 'required|date',
-            'startBalance' => 'numeric|max:1000000000|min:-1000000000',
-            'endBalance'   => 'numeric|max:1000000000|min:-1000000000',
-            'difference'   => 'required|numeric|max:1000000000|min:-1000000000',
+            'startBalance' => ['nullable', new IsValidAmount()],
+            'endBalance'   => ['nullable', new IsValidAmount()],
+            'difference'   => ['required', new IsValidAmount()],
             'journals'     => [new ValidJournals()],
             'reconcile'    => 'required|in:create,nothing',
         ];
diff --git a/app/Http/Requests/RecurrenceFormRequest.php b/app/Http/Requests/RecurrenceFormRequest.php
index c6921aba68..fb4187e512 100644
--- a/app/Http/Requests/RecurrenceFormRequest.php
+++ b/app/Http/Requests/RecurrenceFormRequest.php
@@ -27,6 +27,7 @@ use FireflyIII\Exceptions\FireflyException;
 use FireflyIII\Factory\CategoryFactory;
 use FireflyIII\Models\Recurrence;
 use FireflyIII\Models\TransactionType;
+use FireflyIII\Rules\IsValidPositiveAmount;
 use FireflyIII\Rules\ValidRecurrenceRepetitionType;
 use FireflyIII\Rules\ValidRecurrenceRepetitionValue;
 use FireflyIII\Support\Request\ChecksLogin;
@@ -171,7 +172,7 @@ class RecurrenceFormRequest extends FormRequest
             'transaction_description' => 'required|between:1,255',
             'transaction_type'        => 'required|in:withdrawal,deposit,transfer',
             'transaction_currency_id' => 'required|exists:transaction_currencies,id',
-            'amount'                  => 'numeric|required|gt:0|max:1000000000',
+            'amount'                  => ['required', new IsValidPositiveAmount()],
             // mandatory account info:
             'source_id'               => 'numeric|belongsToUser:accounts,id|nullable',
             'source_name'             => 'between:1,255|nullable',
@@ -179,7 +180,7 @@ class RecurrenceFormRequest extends FormRequest
             'destination_name'        => 'between:1,255|nullable',
 
             // foreign amount data:
-            'foreign_amount'          => 'nullable|gt:0|max:1000000000',
+            'foreign_amount'          => ['nullable', new IsValidPositiveAmount()],
 
             // optional fields:
             'budget_id'               => 'mustExist:budgets,id|belongsToUser:budgets,id|nullable',
diff --git a/app/Rules/IsValidAmount.php b/app/Rules/IsValidAmount.php
new file mode 100644
index 0000000000..6210fc8b13
--- /dev/null
+++ b/app/Rules/IsValidAmount.php
@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace FireflyIII\Rules;
+
+use FireflyIII\Support\Validation\ValidatesAmountsTrait;
+use Illuminate\Contracts\Validation\ValidationRule;
+use Illuminate\Support\Facades\Log;
+
+class IsValidAmount implements ValidationRule
+{
+    use ValidatesAmountsTrait;
+
+    /**
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function validate(string $attribute, mixed $value, \Closure $fail): void
+    {
+        $value = (string)$value;
+
+        // must not be empty:
+        if($this->emptyString($value)) {
+            $fail('validation.filled')->translate();
+            Log::debug(sprintf('IsValidAmount: "%s" cannot be empty.', $value));
+            return;
+        }
+
+        // must be a number:
+        if(!$this->isValidNumber($value)) {
+            $fail('validation.numeric')->translate();
+            Log::debug(sprintf('IsValidAmount: "%s" is not a number.', $value));
+            return;
+        }
+
+        // must not be scientific notation:
+        if($this->scientificNumber($value)) {
+            $fail('validation.scientific_notation')->translate();
+            Log::debug(sprintf('IsValidAmount: "%s" cannot be in the scientific notation.', $value));
+            return;
+        }
+
+        // must be more than minus a lots:
+        if($this->lessThanLots($value)) {
+            $amount = bcmul('-1', self::BIG_AMOUNT);
+            $fail('validation.gte.numeric')->translate(['value' => $amount]);
+            Log::debug(sprintf('IsValidAmount: "%s" must be more than %s.', $value, $amount));
+            return;
+        }
+
+        // must be less than 100 million and 1709:
+        if($this->moreThanLots($value)) {
+            Log::debug(sprintf('IsValidPositiveAmount: "%s" must be more than %s.', $value, self::BIG_AMOUNT));
+            $fail('validation.lte.numeric')->translate(['value' => self::BIG_AMOUNT]);
+        }
+        Log::debug(sprintf('IsValidAmount: "%s" is a valid positive amount.', $value));
+    }
+}
diff --git a/app/Rules/IsValidPositiveAmount.php b/app/Rules/IsValidPositiveAmount.php
new file mode 100644
index 0000000000..f6e4020ed2
--- /dev/null
+++ b/app/Rules/IsValidPositiveAmount.php
@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+namespace FireflyIII\Rules;
+
+use FireflyIII\Support\Validation\ValidatesAmountsTrait;
+use Illuminate\Contracts\Validation\ValidationRule;
+use Illuminate\Support\Facades\Log;
+
+class IsValidPositiveAmount implements ValidationRule
+{
+    use ValidatesAmountsTrait;
+
+    /**
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function validate(string $attribute, mixed $value, \Closure $fail): void
+    {
+        $value = (string)$value;
+        // must not be empty:
+        if($this->emptyString($value)) {
+            $fail('validation.filled')->translate();
+            Log::debug(sprintf('IsValidPositiveAmount: "%s" cannot be empty.', $value));
+
+            return;
+        }
+
+        // must be a number:
+        if(!$this->isValidNumber($value)) {
+            $fail('validation.numeric')->translate();
+            Log::debug(sprintf('IsValidPositiveAmount: "%s" is not a number.', $value));
+            return;
+        }
+        // must not be scientific notation:
+        if($this->scientificNumber($value)) {
+            $fail('validation.scientific_notation')->translate();
+            Log::debug(sprintf('IsValidPositiveAmount: "%s" cannot be in the scientific notation.', $value));
+            return;
+        }
+        // must be more than zero:
+        if($this->lessOrEqualToZero($value)) {
+            $fail('validation.more_than_zero')->translate();
+            Log::debug(sprintf('IsValidPositiveAmount: "%s" must be more than zero.', $value));
+            return;
+        }
+        // must be less than 100 million and 1709:
+        if($this->moreThanLots($value)) {
+            Log::debug(sprintf('IsValidPositiveAmount: "%s" must be less than %s.', $value, self::BIG_AMOUNT));
+            $fail('validation.lte.numeric')->translate(['value' => self::BIG_AMOUNT]);
+        }
+        Log::debug(sprintf('IsValidPositiveAmount: "%s" is a valid positive amount.', $value));
+    }
+}
diff --git a/app/Support/Validation/ValidatesAmountsTrait.php b/app/Support/Validation/ValidatesAmountsTrait.php
new file mode 100644
index 0000000000..29f8d337d1
--- /dev/null
+++ b/app/Support/Validation/ValidatesAmountsTrait.php
@@ -0,0 +1,61 @@
+<?php
+/*
+ * ValidatesAmountsTrait.php
+ * Copyright (c) 2024 james@firefly-iii.org
+ *
+ * This file is part of Firefly III (https://github.com/firefly-iii).
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+namespace FireflyIII\Support\Validation;
+
+trait ValidatesAmountsTrait
+{
+    protected const string BIG_AMOUNT = '100001709';
+
+    final protected function emptyString(string $value): bool
+    {
+        return '' === $value;
+    }
+
+    final protected function isValidNumber(string $value): bool
+    {
+        return is_numeric($value);
+    }
+
+    final protected function scientificNumber(string $value): bool
+    {
+        return str_contains(strtoupper($value), 'E');
+    }
+
+    final protected function lessOrEqualToZero(string $value): bool
+    {
+        return -1 === bccomp($value, '0') || 0 === bccomp($value, '0');
+    }
+
+    final protected function moreThanLots(string $value): bool
+    {
+        return 1 === bccomp($value, self::BIG_AMOUNT) || 0 === bccomp($value, self::BIG_AMOUNT);
+    }
+
+    final protected function lessThanLots(string $value): bool
+    {
+        $amount = bcmul('-1', self::BIG_AMOUNT);
+
+        return -1 === bccomp($value, $amount) || 0 === bccomp($value, $amount);
+    }
+}
diff --git a/app/Validation/AutoBudget/ValidatesAutoBudgetRequest.php b/app/Validation/AutoBudget/ValidatesAutoBudgetRequest.php
index 4c159d9f93..7076524c90 100644
--- a/app/Validation/AutoBudget/ValidatesAutoBudgetRequest.php
+++ b/app/Validation/AutoBudget/ValidatesAutoBudgetRequest.php
@@ -37,6 +37,8 @@ trait ValidatesAutoBudgetRequest
     {
         $data         = $validator->getData();
         $type         = $data['auto_budget_type'] ?? '';
+
+        /** @var null|float|int|string $amount */
         $amount       = array_key_exists('auto_budget_amount', $data) ? $data['auto_budget_amount'] : null;
         $period       = array_key_exists('auto_budget_period', $data) ? $data['auto_budget_period'] : null;
         $currencyId   = array_key_exists('auto_budget_currency_id', $data) ? (int) $data['auto_budget_currency_id'] : null;
@@ -47,12 +49,13 @@ trait ValidatesAutoBudgetRequest
         if ('' === $type || 0 === $type) {
             return;
         }
+        // TODO lots of duplicates with number validator.
         // TODO should be present at more places, stop scientific notification
-        if (str_contains(strtoupper($amount), 'E')) {
+        if (str_contains(strtoupper((string)$amount), 'E')) {
             $amount = '';
         }
         // basic float check:
-        if (!is_numeric($amount) || '' === $amount) {
+        if (!is_numeric($amount) || '' === (string) $amount) {
             $validator->errors()->add('auto_budget_amount', (string) trans('validation.amount_required_for_auto_budget'));
 
             return;
@@ -70,8 +73,6 @@ trait ValidatesAutoBudgetRequest
         // too big amount
         if ((int) $amount > 268435456) {
             $validator->errors()->add('auto_budget_amount', (string) trans('validation.amount_required_for_auto_budget'));
-
-            return;
         }
     }
 }
diff --git a/resources/lang/en_US/validation.php b/resources/lang/en_US/validation.php
index e2dfc845e0..70e9752b58 100644
--- a/resources/lang/en_US/validation.php
+++ b/resources/lang/en_US/validation.php
@@ -34,6 +34,7 @@ return [
     'invalid_query_currency'          => 'Your query contains accounts that have different currency settings, which is not allowed.',
     'iban'                            => 'This is not a valid IBAN.',
     'zero_or_more'                    => 'The value cannot be negative.',
+    'more_than_zero'                  => 'The value must be more than zero.',
     'no_asset_account'                => 'This is not an asset account.',
     'date_or_time'                    => 'The value must be a valid date or time value (ISO 8601).',
     'source_equals_destination'       => 'The source account equals the destination account.',
@@ -124,6 +125,7 @@ return [
     'min.array'                       => 'The :attribute must have at least :min items.',
     'not_in'                          => 'The selected :attribute is invalid.',
     'numeric'                         => 'The :attribute must be a number.',
+    'scientific_notation'             => 'The :attribute cannot use the scientific notation.',
     'numeric_native'                  => 'The native amount must be a number.',
     'numeric_destination'             => 'The destination amount must be a number.',
     'numeric_source'                  => 'The source amount must be a number.',