How to validate CNIC no in mvc by regular expression

I want validate the CNIC no(computed national identity card no). I want to take input from client like (12345-1234567-1) no character except dashes. I wrote below regular expression

[RegularExpression("^[0-9]{5}-[-|]-[0-9]{7}-[-|]-[0-9]{1}")]
public string NICNo { get; set; }

But when I submit the from it shows the whole regular expression in validation error Like below

Solution

You do not need [-|], use

^[0-9]{5}-[0-9]{7}-[0-9]$

See the regex demo. Note the $ at the end requiring the end of string.

Details

^ - start of string
[0-9]{5} - 5 digits
- - a hyphen
[0-9]{7} - 7 digits
- - a hyphen
[0-9] - a single digit (no need "saying" {1})
$ - end of string anchor.

In code:

[RegularExpression("^[0-9]{5}-[0-9]{7}-[0-9]$", ErrorMessage = "CNIC No must follow the XXXXX-XXXXXXX-X format!")]
public string NICNo { get; set; }