If you encounter a payment error on PrestaShop where the amount paid differs from the order total, this may be due to:

• The buyer using the “Back” button in their browser.
• The number of decimal places configured in the PrestaShop Back Office.

Buyer using the backspace key in their browser:

This error occurs if the merchant has configured the following setting in the payment module:

• Payment data entry mode To: Card data entry on payment gateway.
• Cart Management set to Keep Cart (PrestaShop’s default behavior).

And if the buyer performs the following steps:

1. They confirm their order and are redirected to the payment page.
2. They use the back button in their browser to return to the cart page.
3. They modify their cart.
4. They return directly to the payment page.
5. They finalize their payment.

Number of decimal places configured in PrestaShop

To avoid rounding discrepancies, verify that the number of decimal places matches the primary currency of your store.

To verify this information:

1. Sign in to your PrestaShop Back Office.
2. Go to the Preferences menu and click on General.
3. Locate the Decimal Places setting and enter the expected value.
   Example: 2 for the Euro.