All individuals seeking to be registered must complete a Form U4 upon joining a broker-dealer. Additionally, firms and reps have an obligation to amend and update any information required by Form U4 as changes occur within 30 days. For example, if an individual engages in an outside business activity away from the firm, changes their address, or has lien (e.g. tax lien) filed against them, an amended U4 must be filed. Note that if the individual is subject to a statutory disqualification, the amended U4 must be filed within 10 days.