Many states require attorneys to have valid bar numbers in the states they will practice law in when they register for Firm Accounts or are added to existing Firm Accounts.
If an attorney is practicing law out of state (or Pro Hac Vice), then that attorney may require a temporary bar number in order to create a Firm Account (or to be added to an existing Firm Account) in the state they do not normally practice in.
It is much easier for an attorney practicing law out of state to register a new Self-Represented / Individual / Pro Se account instead, as those accounts do not require a bar number for verification.
PLEASE NOTE: Pro Se accounts are not available in all states. To find out which states allow users to file Pro Se, please view the following article.