diff --git a/app/Console/Commands/Correction/CorrectsNativeAmounts.php b/app/Console/Commands/Correction/CorrectsNativeAmounts.php
index bf5d7e98ec..eab4e97525 100644
--- a/app/Console/Commands/Correction/CorrectsNativeAmounts.php
+++ b/app/Console/Commands/Correction/CorrectsNativeAmounts.php
@@ -128,8 +128,8 @@ class CorrectsNativeAmounts extends Command
 
             foreach ($piggyBank->accounts as $account) {
                 $account->pivot->native_current_amount = null;
-                if (0 !== bccomp($account->pivot->current_amount, '0')) {
-                    $account->pivot->native_current_amount = $converter->convert($piggyBank->transactionCurrency, $currency, today(), $account->pivot->current_amount);
+                if (0 !== bccomp((string) $account->pivot->current_amount, '0')) {
+                    $account->pivot->native_current_amount = $converter->convert($piggyBank->transactionCurrency, $currency, today(), (string) $account->pivot->current_amount);
                 }
                 $account->pivot->save();
             }
diff --git a/app/Console/Commands/Upgrade/UpgradesTransferCurrencies.php b/app/Console/Commands/Upgrade/UpgradesTransferCurrencies.php
index 5fe4d06696..a58b1af8bf 100644
--- a/app/Console/Commands/Upgrade/UpgradesTransferCurrencies.php
+++ b/app/Console/Commands/Upgrade/UpgradesTransferCurrencies.php
@@ -39,8 +39,8 @@ class UpgradesTransferCurrencies extends Command
     use ShowsFriendlyMessages;
 
     public const string CONFIG_NAME = '480_transfer_currencies';
-    protected $description          = 'Updates transfer currency information.';
-    protected $signature            = 'upgrade:480-transfer-currencies {--F|force : Force the execution of this command.}';
+    protected                             $description = 'Updates transfer currency information.';
+    protected                             $signature   = 'upgrade:480-transfer-currencies {--F|force : Force the execution of this command.}';
     private array                         $accountCurrencies;
     private AccountRepositoryInterface    $accountRepos;
     private JournalCLIRepositoryInterface $cliRepos;
@@ -68,9 +68,9 @@ class UpgradesTransferCurrencies extends Command
 
         $this->startUpdateRoutine();
         $this->markAsExecuted();
-
-        $this->friendlyInfo(sprintf('Verified currency information of %d transfer(s).', $this->count));
-
+        if ($this->count > 0) {
+            $this->friendlyInfo(sprintf('Verified currency information of %d transfer(s).', $this->count));
+        }
         return 0;
     }
 
@@ -211,14 +211,14 @@ class UpgradesTransferCurrencies extends Command
 
     private function getCurrency(Account $account): ?TransactionCurrency
     {
-        $accountId                           = $account->id;
+        $accountId = $account->id;
         if (array_key_exists($accountId, $this->accountCurrencies) && 0 === $this->accountCurrencies[$accountId]) {
             return null;
         }
         if (array_key_exists($accountId, $this->accountCurrencies) && $this->accountCurrencies[$accountId] instanceof TransactionCurrency) {
             return $this->accountCurrencies[$accountId];
         }
-        $currency                            = $this->accountRepos->getAccountCurrency($account);
+        $currency = $this->accountRepos->getAccountCurrency($account);
         if (null === $currency) {
             $this->accountCurrencies[$accountId] = 0;
 
@@ -290,8 +290,7 @@ class UpgradesTransferCurrencies extends Command
         if (null === $this->sourceTransaction->transaction_currency_id && null !== $this->sourceCurrency) {
             $this->sourceTransaction
                 ->transaction_currency_id
-                     = $this->sourceCurrency->id
-            ;
+                     = $this->sourceCurrency->id;
             $message = sprintf(
                 'Transaction #%d has no currency setting, now set to %s.',
                 $this->sourceTransaction->id,
@@ -313,7 +312,7 @@ class UpgradesTransferCurrencies extends Command
             && null === $this->sourceTransaction->foreign_amount
             && (int) $this->sourceTransaction->transaction_currency_id !== $this->sourceCurrency->id
         ) {
-            $message                                          = sprintf(
+            $message = sprintf(
                 'Transaction #%d has a currency setting #%d that should be #%d. Amount remains %s, currency is changed.',
                 $this->sourceTransaction->id,
                 $this->sourceTransaction->transaction_currency_id,
@@ -336,8 +335,7 @@ class UpgradesTransferCurrencies extends Command
         if (null === $this->destinationTransaction->transaction_currency_id && null !== $this->destinationCurrency) {
             $this->destinationTransaction
                 ->transaction_currency_id
-                     = $this->destinationCurrency->id
-            ;
+                     = $this->destinationCurrency->id;
             $message = sprintf(
                 'Transaction #%d has no currency setting, now set to %s.',
                 $this->destinationTransaction->id,
@@ -359,7 +357,7 @@ class UpgradesTransferCurrencies extends Command
             && null === $this->destinationTransaction->foreign_amount
             && (int) $this->destinationTransaction->transaction_currency_id !== $this->destinationCurrency->id
         ) {
-            $message                                               = sprintf(
+            $message = sprintf(
                 'Transaction #%d has a currency setting #%d that should be #%d. Amount remains %s, currency is changed.',
                 $this->destinationTransaction->id,
                 $this->destinationTransaction->transaction_currency_id,
@@ -382,8 +380,8 @@ class UpgradesTransferCurrencies extends Command
     {
         if ($this->destinationCurrency->id === $this->sourceCurrency->id) {
             // update both transactions to match:
-            $this->sourceTransaction->foreign_amount           = null;
-            $this->sourceTransaction->foreign_currency_id      = null;
+            $this->sourceTransaction->foreign_amount      = null;
+            $this->sourceTransaction->foreign_currency_id = null;
 
             $this->destinationTransaction->foreign_amount      = null;
             $this->destinationTransaction->foreign_currency_id = null;
diff --git a/app/Handlers/Observer/BudgetLimitObserver.php b/app/Handlers/Observer/BudgetLimitObserver.php
index e9e0cf5337..e13bde9327 100644
--- a/app/Handlers/Observer/BudgetLimitObserver.php
+++ b/app/Handlers/Observer/BudgetLimitObserver.php
@@ -25,6 +25,7 @@ declare(strict_types=1);
 namespace FireflyIII\Handlers\Observer;
 
 use FireflyIII\Models\BudgetLimit;
+use FireflyIII\Support\Facades\Amount;
 use FireflyIII\Support\Http\Api\ExchangeRateConverter;
 use Illuminate\Support\Facades\Log;
 
diff --git a/app/Handlers/Observer/TransactionObserver.php b/app/Handlers/Observer/TransactionObserver.php
index d4d79548da..986cda6eeb 100644
--- a/app/Handlers/Observer/TransactionObserver.php
+++ b/app/Handlers/Observer/TransactionObserver.php
@@ -56,7 +56,7 @@ class TransactionObserver
 
     public function updated(Transaction $transaction): void
     {
-        Log::debug('Observe "updated" of a transaction.');
+//        Log::debug('Observe "updated" of a transaction.');
         if (config('firefly.feature_flags.running_balance_column') && self::$recalculate) {
             if (1 === bccomp($transaction->amount, '0')) {
                 Log::debug('Trigger recalculateForJournal');
diff --git a/app/Http/Controllers/Account/EditController.php b/app/Http/Controllers/Account/EditController.php
index 93a1603582..8d1b772256 100644
--- a/app/Http/Controllers/Account/EditController.php
+++ b/app/Http/Controllers/Account/EditController.php
@@ -90,6 +90,7 @@ class EditController extends Controller
         $latitude             = null !== $location ? $location->latitude : config('firefly.default_location.latitude');
         $longitude            = null !== $location ? $location->longitude : config('firefly.default_location.longitude');
         $zoomLevel            = null !== $location ? $location->zoom_level : config('firefly.default_location.zoom_level');
+        $canEditCurrency = $account->piggyBanks()->count() === 0;
         $hasLocation          = null !== $location;
         $locations            = [
             'location' => [
@@ -162,7 +163,7 @@ class EditController extends Controller
 
         $request->session()->flash('preFilled', $preFilled);
 
-        return view('accounts.edit', compact('account', 'currency', 'showNetWorth', 'subTitle', 'subTitleIcon', 'locations', 'liabilityDirections', 'objectType', 'roles', 'preFilled', 'liabilityTypes', 'interestPeriods'));
+        return view('accounts.edit', compact('account', 'currency','canEditCurrency', 'showNetWorth', 'subTitle', 'subTitleIcon', 'locations', 'liabilityDirections', 'objectType', 'roles', 'preFilled', 'liabilityTypes', 'interestPeriods'));
     }
 
     /**
diff --git a/app/Support/Http/Api/ExchangeRateConverter.php b/app/Support/Http/Api/ExchangeRateConverter.php
index dfe9cd7753..c3d847179d 100644
--- a/app/Support/Http/Api/ExchangeRateConverter.php
+++ b/app/Support/Http/Api/ExchangeRateConverter.php
@@ -30,6 +30,7 @@ use FireflyIII\Models\CurrencyExchangeRate;
 use FireflyIII\Models\TransactionCurrency;
 use FireflyIII\Models\UserGroup;
 use FireflyIII\Support\CacheProperties;
+use FireflyIII\Support\Facades\Steam;
 use Illuminate\Support\Facades\Cache;
 use Illuminate\Support\Facades\Log;
 
@@ -72,7 +73,7 @@ class ExchangeRateConverter
         }
         $rate = $this->getCurrencyRate($from, $to, $date);
 
-        return bcmul($amount, $rate);
+        return Steam::bcround(bcmul($amount, $rate), $to->decimal_places);
     }
 
     public function enabled(): bool
diff --git a/app/Transformers/PiggyBankTransformer.php b/app/Transformers/PiggyBankTransformer.php
index 6c76f73a7b..c1cf567fa3 100644
--- a/app/Transformers/PiggyBankTransformer.php
+++ b/app/Transformers/PiggyBankTransformer.php
@@ -136,7 +136,7 @@ class PiggyBankTransformer extends AbstractTransformer
             $return[] = [
                 'id'             => $account->id,
                 'name'           => $account->name,
-                'current_amount' => $account->pivot->current_amount,
+                'current_amount' => (string) $account->pivot->current_amount,
                 // TODO add balance, add left to save.
             ];
         }
diff --git a/resources/lang/en_US/firefly.php b/resources/lang/en_US/firefly.php
index 5e5b8d5092..6921b61bb6 100644
--- a/resources/lang/en_US/firefly.php
+++ b/resources/lang/en_US/firefly.php
@@ -1913,6 +1913,7 @@ return [
     'extension_date_is'                                    => 'Extension date is {date}',
 
     // accounts:
+    'account_locked_currency' => 'The currency of this account must remain :name as long as piggy banks are linked to it.',
     'i_am_owed_amount'                                     => 'I am owed amount',
     'i_owe_amount'                                         => 'I owe amount',
     'inactive_account_link'                                => 'You have :count inactive (archived) account, which you can view on this separate page.|You have :count inactive (archived) accounts, which you can view on this separate page.',
diff --git a/resources/views/accounts/edit.twig b/resources/views/accounts/edit.twig
index 9b9ce38834..e5cbdb0266 100644
--- a/resources/views/accounts/edit.twig
+++ b/resources/views/accounts/edit.twig
@@ -27,9 +27,12 @@
                     </div>
                     <div class="box-body">
                         {{ ExpandedForm.text('name', account.name) }}
-                        {% if account.accountType.type == 'Default account' or account.accountType.type == 'Asset account' or objectType == 'liabilities' %}
+                        {% if canEditCurrency and (account.accountType.type == 'Default account' or account.accountType.type == 'Asset account' or objectType == 'liabilities') %}
                             {{ CurrencyForm.currencyList('currency_id', null, {helpText:'account_default_currency'|_}) }}
-
+                        {% endif %}
+                        {% if not canEditCurrency and (account.accountType.type == 'Default account' or account.accountType.type == 'Asset account' or objectType == 'liabilities') %}
+                            <input type="hidden" name="currency_id" value="{{ currency.id }}"/>
+                            {{ ExpandedForm.staticText('currency_id', trans('firefly.account_locked_currency', {name: currency.name})) }}
                         {% endif %}
 
                         {% if objectType == 'liabilities' %}