IBAN-Formatted Account Display Regex for Python

What this pattern does

This page provides a well-structured, multi-part regular expression for matching iban-formatted account display, 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

# IBAN-Formatted Account Display
# ReDoS-safe | RegexVault — Finance > Financial Formats

import re

ibanformatted_account_display_pattern = re.compile(r'^[A-Z]{2}[0-9]{2}(?:\s[A-Z0-9]{4})+(?:\s[A-Z0-9]{1,4})?$')

def validate_ibanformatted_account_display(value: str) -> bool:
    return bool(ibanformatted_account_display_pattern.fullmatch(value))

# Example
print(validate_ibanformatted_account_display("GB29 NWBK 6016 1331 9268 19"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Finance > Financial Formats 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

Display-formatted IBANs use spaces every 4 characters (with the final group being 1-4 chars). Strip all spaces before any processing, lookup, or comparison. Store IBANs without spaces.