Regex for Canadian Postal Code — Pattern Explained with Examples

Canadian postal codes are six-character alphanumeric codes in an alternating letter-digit pattern separated by a space. This pattern validates the standard A#A #A# format used by Canada Post for mail sorting and delivery.

The Pattern

/^[A-Z]\d[A-Z]\s?\d[A-Z]\d$/i

Pattern Breakdown

Matches

• K1A 0B1
• H0H 0H0
• V6B 4Y8
• M5V 2T6
• T2P 1J9

Does NOT Match

• K1A0B1 (no space)
• 12345
• K1A 0B
• ABCD
• A1A1A1A1
• K1A-0B1

Language Examples

JavaScript

const caPostalRegex = /^[A-Z]\d[A-Z]\s?\d[A-Z]\d$/i;
console.log(caPostalRegex.test('K1A 0B1')); // true
console.log(caPostalRegex.test('12345'));    // false

Python

import re
pattern = r'^[A-Z]\d[A-Z]\s?\d[A-Z]\d$'
print(bool(re.match(pattern, 'K1A 0B1', re.IGNORECASE))) # True
print(bool(re.match(pattern, '12345', re.IGNORECASE)))    # False

Common Pitfalls

• The first letter denotes a province or region (K for Ontario, V for British Columbia, etc.) — some letters like D, F, I, O, Q, and U are not used in the first position by Canada Post
• The space is technically optional but strongly recommended — Canada Post formatting standards include it
• Input should be reformatted to uppercase for consistency, even though the pattern is case-insensitive
• The letters D, F, I, O, Q, and U do not appear in Canadian postal codes at all due to optical character recognition issues
• A valid format does not guarantee a real postal code — the code must exist in the Canada Post database for delivery

Real-World Use Cases

• Canadian e-commerce platforms — validate shipping addresses for orders within Canada
• Address autocomplete services — validate partial postal code input before suggesting addresses
• Mailing list hygiene — clean and standardize postal codes in customer databases before bulk mailings

FAQ

Related Patterns

Regex for UK Postcode Regex for ZIP/Postal Code