Canadian postal code regex?

Question

In the postal code field only the following format should be valid.

B1C 2B3 or B1C3D3

how to write a regex for this?

Edited:

^([a-zA-Z]\d[a-zA-z]( )?\d[a-zA-Z]\d)$

This is my regex but it only accepting B1C C1B (notice space in between ) format. even with out space should be valid

This is C# not VB.NET but I expect it translates: http://stackoverflow.com/questions/1146202/canada-postal-code-validation — Rup, May 17 '13 at 17:20
If these are the only three values that you expect, what's wrong with `B1C|C1B|B1CC1B` regex? — Sergey Kalinichenko, May 17 '13 at 17:21
@SLaks : "^([a-zA-Z]\d[a-zA-z]( )?\d[a-zA-Z]\d)$" this is my regex but it only accepting B1C C1B (notice space in between ) format. even with out space should be valid — software, May 17 '13 at 17:23
Those aren't valid Canadian postal codes. The format is `A0A 0A0`, where `A` stands for a letter and `0` stands for a digit. — Vadim K., May 17 '13 at 17:25

score 4 · Answer 1 · edited Apr 15 '15 at 22:31

4

There are some real inconsistencies here. The Regex you provided ^([a-zA-Z]\d[a-zA-z]( )?\d[a-zA-Z]\d)$ matches what was stated by Scott regarding the correct Canadian format. However, the examples you provided do not follow the format B1C C1B or B1CC1B.

To add insult to injury, the Regex you provided works with the proper Canadian format. So there isn't any real reason to change it. I mean, I would change it to this ^([a-zA-Z]\d[a-zA-Z]\s?\d[a-zA-Z]\d)$ so that the single space isn't grouped, but that's just me.

However, as far as using it, it could be used in C# like this:

var matches = Regex.Match(inputString, @"^([a-zA-Z]\d[a-zA-Z]( )?\d[a-zA-Z]\d)$");
if (!matches.Success) {
    // do something because it didn't match
}

and now that it's been tagged with VB.NET:

Dim matches = Regex.Match(inputString, "^([a-zA-Z]\d[a-zA-Z]( )?\d[a-zA-Z]\d)$")
If Not matches.Success Then
    ' do something because it didn't match
End If

edited Apr 15 '15 at 22:31

Corb3nik

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answered May 17 '13 at 17:21

Mike Perrenoud

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5

Actually the regex is `[A-Z][0-9][A-Z] ?[0-9][A-Z][0-9]` AAA AAA is not a valid Canadian zip code. neither is `B1C\t0A2` (the op's orignal example was wrong too) – Scott Chamberlain May 17 '13 at 17:25
@ScottChamberlain, my apologies, I'll take the OP's current Regex and fix it. – Mike Perrenoud May 17 '13 at 17:27
@ScottChamberlain, I fixed it, but there are some real inconsistencies in the OP's question. – Mike Perrenoud May 17 '13 at 17:34
This could be shortened with a case insensitive flag and then `a-zA-Z` could be `A-Z` – Dylan Valade May 12 '15 at 01:39

score 4 · Answer 2 · answered May 17 '13 at 18:39

You'd want to validate the postal code against the address database. Not every postal code in the format A0A0A0 is a valid Canadian postal code. Examples of postal codes that do not exist:

Z0Z0Z0
Z9Z9Z9
Y7Y7Y7

Regarding preliminary checking, the easiest would probably be one with pre-processing of the value by VB.NET code. You need to remove spaces and convert to upper case. Then your regex is very simple: ([A-Z]\d){3}. And here is the full code for testing:

Imports System.Text.RegularExpressions

Module Module1
  Sub Main()
    Console.WriteLine(CanBeValidCanadianPostalCode("B1C 2B3")) 'prints True
    Console.WriteLine(CanBeValidCanadianPostalCode("B1C3D3")) 'prints True
  End Sub

  Private Function CanBeValidCanadianPostalCode(postal_code As String) As Boolean
    Return Regex.IsMatch(postal_code.Replace(" ", "").ToUpper, "([A-Z]\d){3}")
  End Function
End Module

score 2 · Answer 3 · answered Jun 01 '15 at 06:22

2

Use the below regex for Canadian ZIP code validations

^[ABCEGHJKLMNPRSTVXY]{1}\d{1}[A-Z]{1} *\d{1}[A-Z]{1}\d{1}$

answered Jun 01 '15 at 06:22

Arun Kumar S K

41
1
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This is the proper answer. – Hal Oct 27 '16 at 15:58

Canadian postal code regex?

3 Answers3