Notify USCIS if your circumstances unexpectedly change, such as:

• You have moved and want to know how to give us your new address
• You filed a Form I-130, Petition for Alien Relative, as a permanent resident, and then became a U.S. citizen
• You have a pending Form I-129, Petition for a Nonimmigrant Worker, and you need to change the names of persons you included on the petition
• You have a pending Form I-129, Petition for a Nonimmigrant Worker, and  you need to change the consulates or ports of entry where the individuals will apply for their visa or entry
• You absolutely cannot make it to a scheduled interview that we requested, call before the interview date as far in advance as possible. (Understand that rescheduling can delay processing. We will only reschedule if emergency reasons outside your control prevent you from keeping your appointment. Certain kinds of interviews cannot be rescheduled. When you call the USCIS Contact Center, you will need to explain why it is impossible for you to keep your appointment. The office where your interview was scheduled will make the decision about whether to grant your request to change your appointment, and will notify you directly.)

Notify USCIS if you notice an error in our correspondence, such as:

• An error in the information on the last notice we sent you
• An error on a document we issued. You will have to file an application to replace it, and you will have to return the document when you apply. (If the error was caused by USCIS and you prove this, you may be able to file an application without a fee.)

Notify USCIS if you are concerned you haven't received something important from us, such as:

• You mailed your application or petition more than 30 days ago to a Service Center or to our National Benefits Center, and have not yet received a receipt in the mail
• You did not get any other kind of notice and you have a receipt number but "My Case Status" states that we sent you a notice (other than the receipt notice) more than 14 days ago
• You filed several related cases together and are concerned because you received a decision about some of the cases but not the others
• You submitted original documents with your case and you want to request documents be returned to you while your case is pending. (We recommend you wait until the case is finished to ask for the return of original documents to avoid unexpected delays in your case.)