C#- Validation for US or Canadian zip code

Question

I am using following method to validate US or Canadian zip code, but i think it is not working fine for me. Please suggest me the changes in the regular expression.

Answer 1

    var _usZipRegEx = @"^\d{5}(?:[-\s]\d{4})?$";
    var _caZipRegEx = @"^([ABCEGHJKLMNPRSTVXY]\d[ABCEGHJKLMNPRSTVWXYZ])\ {0,1}(\d[ABCEGHJKLMNPRSTVWXYZ]\d)$";

    private bool IsUSOrCanadianZipCode(string zipCode)
    {
        var validZipCode = true;
        if ((!Regex.Match(zipCode, _usZipRegEx).Success) && (!Regex.Match(zipCode, _caZipRegEx).Success))
        {
            validZipCode = false;
        }
        return validZipCode;
    }
}