New Zealand Bank Account Number Regex for Python

What this pattern does

This page provides a well-structured, multi-part regular expression for matching new zealand bank account number, ported and verified for Python. Financial data validation has zero tolerance for false negatives — a missed invalid entry can corrupt downstream calculations. The snippet below is ready to drop into your Python project — whether you're validating in a Django view, a FastAPI endpoint, or a standalone data processing script.

Python Implementation

# New Zealand Bank Account Number
# ReDoS-safe | RegexVault — Finance > Bank Identifiers

import re

new_zealand_bank_account_number_pattern = re.compile(r'^(?:([0-9]{2})-([0-9]{4})-([0-9]{7})-([0-9]{2,3}))$')

def validate_new_zealand_bank_account_number(value: str) -> bool:
    return bool(new_zealand_bank_account_number_pattern.fullmatch(value))

# Example
print(validate_new_zealand_bank_account_number("01-0137-0000000-00"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Finance > Bank Identifiers category and carries a ReDoS-safe certification. That matters for Python developers because particularly important in Python web servers where CPU-bound regex operations can stall concurrent request handling. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

Format: 2-digit bank + 4-digit branch + 7-digit account + 2-3 digit suffix. Capture groups: 1=bank, 2=branch, 3=account, 4=suffix. Validate bank codes against RBNZ register.