Go to Settings>Banking>Credit Card Settings.
In the bottom right corner, check C(F)ee Active.
For Rounding, either select 0 for the Nearest Penny or 1 for the Nearest Dollar.
Type in the percentage for your rate in the CFee Rate field. If you would like to set a minimum fee, type the amount in the Minimum field.
To assign the General Ledger account for posting the fee, select Setup.
Click the to search for the correct account code. Highlight the correct one, then click Select. Check that the correct code is entered in the Account Code field. Select OK.
The Convenience Fee message will appear.
Once the fee is set up, when you run a payment, the Applying Convenience Fee to Invoice message will appear.
You can bypass convenience fees for a debit card or manually disable them for certain transactions.