Until recently, if an applicant’s naturalization petition was denied, he or she would be instructed to file the appeal with the USCIS office that made the Decision. Now, however, it appears that appeals of naturalization denials need to be filed with the USCIS lockbox in Phoenix, Arizona.
The USCIS denial letter should also contain an instruction as to where to file the appeal. All applicants only have thirty days to file the appeal, and so it becomes extremely important to file the appeal with the correct USCIS office in order to avoid missing the deadline.