A legal permanent resident or a Green card holder who has lived in the United States for five years or more can apply for U.S. Citizenship. Before applying for citizenship, the USCIS have certain requirements that the holder needs to meet for before citizenship is granted to him/her. If they meet all the requirements they can apply for citizenship by filing Form N-400, Application for naturalization with the USCIS along with the required documents including a copy of green card.
The following are the cases under which an application for U.S. citizenship can be denied:
1) Failure of Civics Test:
Once the application for citizenship is under process and checked for accuracy, the USCIS will require the holder to appear for a Biometric scans following which the applicant will be scheduled a naturalization interview where they need to take a Citizenship test. The applicant must prove that he is good enough to read, write and speak in English, after which they will have to take a Civics test which will be comprised of 10 questions. The minimum requirement by the USCIS is six correct answers out of 10 to be correct. In case of the applicant failing to answer 6 questions correctly, he will be given another chance to take the test after a period of 90 days. If he/she fails this test again, the application will be rejected.
This is only for the applicants who have applied for Green Card and come under the three year rule. At the time of filing for Green card, the applicant needs to prove they are still married to the spouse who has sponsored them for legal permanent resident status and also is a citizen of the United States. Failing which, the application will be denied.
3) Criminal Activities:
If the applicant has a police record for serious crimes such as murder or an aggravated felony, he/she cannot apply for citizenship. Once the USCIS comes to know of the police record, the application will be denied and deportation procedures will be begin.
4) Evidence of Good moral character:
The applicants must be able to prove he is of good moral character by paying for child support, not lying to immigration authorities, by paying taxes, and have no pending criminal cases under their name (only for those who have committed crimes) failing which the USCIS will reject the application.
However, the applicant can still appeal the denial of their applications in case USCIS denies their application.