Monetary Amount with Currency Code Regex for Python

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching monetary amount with currency code, 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

# Monetary Amount with Currency Code
# ReDoS-safe | RegexVault — Finance > Currency & Money

import re

monetary_amount_with_currency_code_pattern = re.compile(r'^(?:([A-Z]{3})\s)?-?(?:(?:[0-9]+(?:,[0-9]{3})*)|0)(?:\.[0-9]{1,4})?(?:\s([A-Z]{3}))?$')

def validate_monetary_amount_with_currency_code(value: str) -> bool:
    return bool(monetary_amount_with_currency_code_pattern.fullmatch(value))

# Example
print(validate_monetary_amount_with_currency_code("USD 1,234.56"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Finance > Currency & Money 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

Capture group 1: prefix currency code, group 2: suffix currency code. Validate that only one is present at application level. Up to 4 decimal places to accommodate currencies like JPY (0) and BHD (3).