validate

Validates an Indian Financial System Code (IFSC).

Input normalisation applied before validation (in order):

1. Trim leading/trailing whitespace

2. Strip all internal whitespace (covers copy-paste with spaces)

3. Uppercase all characters

After normalisation, checks are applied in order — first failing check wins:

• InvalidReason.EMPTY if the result is blank

• InvalidReason.WRONG_LENGTH if length is not 11

• InvalidReason.INVALID_FORMAT if the string does not match [A-Z]{4}0[A-Z0-9]{6}

The regex encodes all structural constraints simultaneously:

• Characters 1–4 must be [A-Z]

• Character 5 must be '0' (RBI reserved position)

• Characters 6–11 must be [A-Z0-9]

Note: Hyphens are not stripped. "HDFC-0000001" normalises to a 12-character string and returns InvalidReason.WRONG_LENGTH.

Parameters

Samples

check(IFSC.validate("HDFC0000001") == ValidationResult.Valid)
check(IFSC.validate("HDFC1000001") is ValidationResult.Invalid)