Hello, @AgaB 

Welcome to the Docusign Community!

Have you tried to find an ready to go REGEX mask in the Regex Library site?

https://regexlib.com/

Perhaps, you will find one doing what you want or at least, give ideas to do it.

Best,

Alexandre

Thanks @Alexandre.Augusto - I used similar sites to create regex pattern with letters. 

I will check out the one you recommended - Thanks,

Docusign has some good examples how to create numbers validations but sadly not letters 

@AgaB - 

Your regular expression is almost correct, but there's a small mistake in it. Instead of using (\s) to match spaces between digits and letters, you should use \s* to match zero or more spaces. Also, you can simplify it a bit. Here's the corrected version:

regex

Copy code

^([0-9]{9})\s*([A-Za-z]{2})\s*([0-9]{4})$

In this expression:

• ^ asserts the start of the string.
• ([0-9]{9}) matches exactly 9 digits.
• \s* matches zero or more spaces.
• ([A-Za-z]{2}) matches exactly 2 letters, either uppercase or lowercase.
• \s* matches zero or more spaces.
• ([0-9]{4}) matches exactly 4 digits.
• $ asserts the end of the string.

This should match the pattern you described: 9 digits followed by 2 letters followed by 4 digits, with optional spaces in between.

@JohnSantos  - thanks so much for your feedback!

it works perfectly - I just completed couple of tests, and all works as expected. 

cheers!