Java Regex – Canada Postal Code Validation

In this java regex tutorial, we will Learn to use regular expressions to validate canadian postal zip codes. You can modify the regex to suit it for any other format as well.

1. What is a valid canadian postal code

A Canadian postal code is a six-character string that forms part of a postal address in Canada.

A valid canadian postcode is –

• in the format A1A 1A1, where A is a letter and 1 is a digit.
• a space separates the third and fourth characters.
• do not include the letters D, F, I, O, Q or U.
• the first position does not make use of the letters W or Z.

Regex : ^(?!.*[DFIOQU])[A-VXY][0-9][A-Z] ?[0-9][A-Z][0-9]$

In Above regex, the negative lookahead at the beginning of this regular expression prevents D, F, I, O, Q, or U anywhere in the subject string. The <[A-VXY]> character class further prevents W or Z as the first character.

2. Canada Postal Code Validation Example

List<String> zips = new ArrayList<String>();
      
//Valid ZIP codes
zips.add("K1A 0B1");  
zips.add("B1Z 0B9");  

//Invalid ZIP codes
zips.add("K1A 0D1");  
zips.add("W1A 0B1");  
zips.add("Z1A 0B1");

String regex = "^(?!.*[DFIOQU])[A-VXY][0-9][A-Z] ?[0-9][A-Z][0-9]$";

Pattern pattern = Pattern.compile(regex);

for (String zip : zips)
{
	Matcher matcher = pattern.matcher(zip);
	System.out.println(matcher.matches());
}

Output:

true
true

false
false

That was pretty easy, right? Drop me your questions related to how to validate canadian postal zip code using regular expressions.

Happy Learning !!