Thank you so much for the thorough reply! So just to clarify, is us modifying the already-sent invoice to remove the CC fee and re-sending it to the customer the only way for them to not have to pay the fee? Is there no way that the customer can simply opt not to pay the CC processing fee line item at the time of payment, or simply pay the invoice amount itself minus the CC processing fee?

And if they did pay a different amount than the invoice total due, can we then modify the total invoice amount on the already-Paid invoice to reflect the actual amount paid?'

Thanks so much for your help!