We are evaluating an embedded online checkout for an Arizona (US) merchant using Web Payments SDK plus Payments API. Before implementing or enabling a surcharge, we need confirmation of the supported approach—not a programming walkthrough.
Desired behavior:
- Eligible credit card: a separately disclosed surcharge, within applicable limits, shown before the buyer confirms payment.
- Debit, prepaid, gift cards, and unknown card types: no surcharge.
Customer Success referred us here and confirmed that Square Online does not support automatic card surcharges. The developer surcharge documentation describes Terminal API and Mobile Payments SDK, while Web Payments SDK exposes card-type information.
Could a Square Developer Advocate please clarify:
- Does Square permit and support a merchant-calculated credit-only surcharge in a US Web Payments SDK + Payments API integration?
- If yes, should it be represented as an Orders API service charge, or is there a dedicated payment field or other required mechanism?
- How should the server verify credit/prepaid eligibility before authorization, without trusting client-supplied card-type data or storing a card on file unnecessarily?
- What Square enrollment, card-network notification, disclosure, receipt, and surcharge-limit requirements apply to this integration?
- If this flow is unsupported, is there a supported online API alternative that applies the fee only to eligible credit cards?
No surcharge is enabled. We want to confirm Square support and requirements before building this into checkout. Thank you.