Mintly Bank Account Checker API (1.2.1)

Every request must carry an X-API-KEY header set to your organisation's unique key. Keep this secret — it identifies and bills your account. You can find your key in your Mintly account.

X-API-KEY: YOUR_API_KEY

Call GET /identity to confirm a key works before wiring up anything else.

All Mintly APIs are served over HTTPS with TLS 1.2, so data is encrypted in transit. Never embed your API key in client-side code — proxy requests through your own backend instead.

Environment	Base URL	Counts towards usage
Production	https://api.mintly.uk/bankAccount/v1	Yes
Sandbox	https://sandbox.mintly.uk/bankAccount/v1	No

Develop against the sandbox first, so you can exercise every error path without consuming your allowance. The sandbox still requires your API key, but it returns a fixed set of responses and cannot perform real checks.

Sandbox test values — every other input returns 404:

Input	Value
Sort code	424242
Account number	42424242
SWIFT/BIC	TEST4242XXX
IBAN	GB42SAND424242 42424242

Each request to production counts as one check against your monthly allowance. If your plan includes 10,000 checks, that is 10,000 requests.

We use standard HTTP status codes, including but not limited to:

Status	Meaning
200 OK	The request succeeded and produced a valid check.
400 Bad request	Something was wrong with the request. Check the error message in the response.
401 Unauthorised	Your credentials are invalid or have expired.
403 Forbidden	Authentication failed — the key has expired, or no key was provided.
404 Not found	The requested resource does not exist, so the result is invalid.
429 Too many requests	You have exceeded the rate limit. Wait, then retry with exponential backoff.
500 Server error	Something went wrong on our side — get in touch so we can look into it.

Errors return a Status of Error or Invalid alongside a human-readable Message.

The API is designed to be backwards compatible: changes should not disrupt existing integrations. We may add new fields or response values, but we will not remove or rename existing fields, nor change their behaviour in a way that breaks current usage. We follow semantic versioning for API releases.

Build your integration to handle non-breaking changes gracefully, such as new fields or optional parameters. If a breaking change ever becomes necessary, we will give advance notice and a clear migration path, and keep the existing version available for a defined deprecation period.

Install the Mintly Bank Account Checker agent skill for AI-assisted integration help inside your editor. Once installed, invoke /mintly-api to generate client code, handle errors, and test against the sandbox.

Download the agent skill

Built on the Agent Skills open standard, it works with Claude Code, VS Code (GitHub Copilot), OpenAI Codex, Cursor, Gemini CLI, and many more.