Is the merchant allowed to charge the customer the fee that the merchant is charged by Visa or Mastercard for accepting payment with the credit card?

In general, merchants are not allowed to pass on the transaction fees charged by Visa or MasterCard directly to customers. This practice, known as "surcharging," is regulated and varies by country and card network rules. Some jurisdictions permit surcharging under specific conditions, while others prohibit it altogether. Merchants should check local laws and card network guidelines before implementing any surcharge policies.