FIO Address

A FIO Address consists of a username and a domain delimited by an @ symbol, there are not specific requirements around a FIO Address username, but there are format restrictions around the FIO Address as a whole, and then separate requirements for a FIO Domain in particular.

  FIO Address ([email protected]) FIO Domain
Min. Chars 3 1
Max Chars 64 (including FIO Domain) 62
Characters allowed ASCII a-z 0-9 - (dash) with single @ (at sign) ASCII a-z 0-9 - (dash)

FIO Address validation using regex

Regex validation may be used. For example, the following regex may be used to validate a FIO Address:

^(?:(?=.{3,64}$)[a-zA-Z0-9]{1}(?:(?!-{2,}))[a-zA-Z0-9-]*(?:(?<!-))@[a-zA-Z0-9]{1}(?:(?!-{2,}))[a-zA-Z0-9-]*(?:(?<!-))$)