API terms

Last updated: 7 October 2026

These terms apply when you use the CardFeeCalc API at cardfeecalc.com/api ("API"). The provider is CardFeeCalc ("we", "us").

Informational estimates

API responses are estimates based on published processor rates and surcharge rules we track on the public site. They are not quotes from any payment company, legal advice, or tax advice. You are responsible for how you use the data.

No warranty

The API is provided "as is" without warranties of any kind. We do not guarantee uninterrupted service, perfect accuracy, or that rate tables are complete for your situation.

Fair use and keys

Do not share API keys publicly, scrape beyond your plan limits, or attempt to disrupt the service. We may suspend keys that abuse the API or violate these terms. One active free key per email address unless we agree otherwise.

Paid plans and billing

When paid plans launch, they will be sold through Lemon Squeezy (merchant of record). You will be able to cancel at any time through the Lemon Squeezy customer portal, and access will continue until the end of the current billing period. Refunds will follow Lemon Squeezy's policies.

Changes

We may change endpoints, limits, or these terms with reasonable notice on the API docs page. Continued use after changes means you accept the updated terms.

Contact

Questions: [email protected].