Service Fee Related to Credit Card Payment

In my experience, AWS does not apply an additional fee or surcharge when paying by credit card. Only the cost of the service for which a charge is applied, and then any applicable taxes for the jurisdiction in which your account is registered (e.g. VAT, GST, etc.).

I don't work for AWS so I cannot guarantee that a credit card fee will never be charged in your jurisdiction, for absolute clarity on this it is best to log a billing support call with AWS https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/billing-get-answers.html#billing-support