In most cases, yes—it's legal to surcharge credit cards. ing to federal law, there's a 4% maximum allowable surcharge on credit card transactions. Debit card surcharging is illegal in all 50 states.
If doing so doesn't create financial hardships for you in other areas, paying your credit card bill in multiple early payments is typically not a bad idea. If one or more partial payments occur prior to the end of your billing cycle, it could improve your credit score.
Credit card processing fees encompass three types of fees (interchange, assessment and payment processing) that get distributed to three separate financial institutions (issuing bank for the card, credit card network and payment processor) involved in facilitating the card payment process.
These expenses fall under the category of “miscellaneous expenses”, where you'll be allowed to describe them as “credit card processing fees”.