Can I pass card fees on to my customers?

No. Your customer pays exactly the total on the invoice, whichever way they pay, and the card fee comes out of your payout. DeskOps doesn't add a card surcharge or a convenience fee, because the rules are strict and differ by state: some states ban surcharges, others cap them or set how the price must be shown, and card networks don't allow a surcharge on debit or prepaid cards at all. What works everywhere: build your card costs into your prices, so there is one price however someone pays, or turn on bank payments, which cost you less to accept. If you type a card-fee line onto an invoice or quote yourself, it is charged whatever the customer pays with, including bank transfer and cash, and the line says so while you write it. If you want a surcharge anyway, check your state's rules and your card processor's requirements first.