Should a machine shop pass credit card fees to customers?

Calculate the effect on this order's margin

Assume the invoice covers 50 machined aluminum housings at $100 each, with $4,000 of material, conversion, inspection and outside-service cost. Exclude tax, freight and fixed transaction fees from this example. Absorbing a 3% processing fee reduces the amount retained to $4,850 and leaves $850 of job profit, or 17% of the original sales amount.

Adding 3% to the invoice would collect $5,150, but if the same assumed processor charges 3% on that total, the processing cost is $154.50. The shop retains $4,995.50. Exactly netting $5,000 under these assumptions would require $5,000 / 0.97 = $5,154.64, a 3.0928% addition. That arithmetic does not authorize the fee: it exceeds Visa's published 3% ceiling and must not become an automatic gross-up policy.

Check the card network before setting a percentage

Visa's US merchant Q&A, checked October 30, 2026, limits a credit-card surcharge to the lower of the applicable merchant discount rate or 3%. It excludes debit and prepaid cards, requires at least 30 days' advance notice to the acquirer, and requires entry, transaction and receipt disclosures. Selecting credit at a terminal does not turn a debit card into a surcharge-eligible credit card.

Mastercard's US merchant page, checked the same day, also excludes debit and prepaid cards. It requires advance notification to Mastercard and the acquirer at least 30 days before implementation. Its brand-level rule uses the lower of the effective acceptance rate or its 4% maximum cap, with additional product-level and competing-network conditions. A higher Mastercard ceiling does not mean the shop can apply that rate to every card.

Network permission does not settle applicable law. Have your processor or acquirer confirm the supported implementation and obtain qualified advice for the jurisdictions involved. Neither a B2B invoice nor the label convenience fee automatically bypasses surcharge rules. This guide intentionally supplies no nationwide list of states where a fee is permitted.

Choose the commercial policy before quoting

For occasional prototype customers, card acceptance may reduce collection effort or help the buyer place an order immediately. For a recurring production account, offer another agreed payment method and compare its actual fees and collection timing. Do not assume ACH is free or that a card guarantees final collection; use the terms of your own provider.

If you absorb processing, include its expected cost in your pricing model without charging it twice. If your approved policy uses a surcharge, put the applicable method, percentage and disclosure into the quote and payment flow before the buyer commits. An invoice footer added after acceptance creates a commercial dispute even before anyone asks about the network rules.

What to do before the next card invoice

Send the processor your actual transaction type, invoice sizes, card mix and operating locations. Request written confirmation of eligibility, applicable caps, notice, receipt handling and debit exclusion. Then test a credit payment and a debit payment in the supported configuration.

For an absorbed-fee policy, a simple quote sentence is enough: ‘Card payments are accepted at the quoted price; bank payment instructions are available on request.’ Write surcharge wording only after the implementation and rate are confirmed, and display the final dollar amount before the customer pays.

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