Singapore UEN (Unique Entity Number) Regex for Python

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching singapore uen (unique entity 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

# Singapore UEN (Unique Entity Number)
# ReDoS-safe | RegexVault — Finance > Tax & Registration

import re

singapore_uen_unique_entity_number_pattern = re.compile(r'^(?:[0-9]{8}[A-Z]|[0-9]{9}[A-Z]|[RT][0-9]{2}[A-Z]{2}[0-9]{4}[A-Z]|S[0-9]{2}[A-Z]{2}[0-9]{4}[A-Z])$')

def validate_singapore_uen_unique_entity_number(value: str) -> bool:
    return bool(singapore_uen_unique_entity_number_pattern.fullmatch(value))

# Example
print(validate_singapore_uen_unique_entity_number("200312345A"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Finance > Tax & Registration 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

Business types: 9-char (8 digits + check letter) for older entities, 10-char for newer. T/R/S prefixes indicate specific registration types (GST, foreign entity, societies).