What should applicants do if they change their address after filing the N-400?

When an applicant changes their address after filing the N-400, it is crucial for them to keep USCIS informed to ensure they receive all important correspondence regarding their application process. Notifying USCIS using Form AR-11, which is specifically designated for notifying the agency about a change of address, ensures that the applicant's records are updated in the system. This step is essential to avoid any disruptions in communication, which could lead to missed notifications about interviews or additional information requests.

Using Form AR-11 not only maintains good standing during the application process but also underscores the importance of keeping personal information current with the immigration authorities. The other options do not address the need for a formal update to USCIS in a timely manner, which could potentially lead to complications or delays in the processing of the application.