I am trying to create a validation rule for US format number and using the following regex Validation
NOT(REGEX(Phone, "\\D*?(\\d\\D*?){10}"))
The above seems like a standard regex which will only allow saving for (000) 000-0000 format number.
However, if I enter characters in the following format
(000) 000-0000yyy. It is still allowing save.
Best Answer
You can try the below one as this could make sure that the phone contains only numbers.