IBAN validation
Inspect country format, length and MOD-97 results. National account checks and bank reference coverage may be partial; read the result’s notes.
Online Format Validators & Checkers
A passing format check answers a narrow question. Choose the validator that matches your input and read each reported layer separately: syntax, length, checksum and any supported reference checks.
Tools in this category
Search all tools →Which tool fits your task?
BIC / SWIFT syntax
Check the shape of an 8- or 11-character code. Syntactic correctness does not establish that a bank is registered or a branch exists.
Card-number formats
Inspect network shape, length and the Luhn checksum. These checks do not verify a cardholder, balance or authorization.
Negative test cases
Change one property at a time so a rejection has an interpretable cause. Do not use a random malformed string as your entire validation test suite.
A useful workflow
- 01
Choose the format-specific validator and use a synthetic fixture.
- 02
Compare a passing example with a targeted negative case.
- 03
Preserve the reported coverage and route payment scenarios to a provider sandbox.
Worked example
Validation matrix case A: expected length and format case B: one missing character case C: one deliberately wrong check digit record: which check failed and which checks were not performed never infer: real account ownership or payment approval