I have used regex(.,'^[0-8]{9}$') to restrict phone number to a must 9 digits under constraint

[Kal_Lam]

@LastyJakom, this post discussed previously could also solve your issue:

How to limit my id number entry to 10 characters?

Hi @PamelaLlanes, Try using the regex code regex(., '^[0-9]{10}$') with the question type as text. A similar example has already been discussed in the forum: To learn more on regex please feel free to visit our support article Restricting text responses with regular expressions. Have a great day!