You may now use an approved credit card to pay your Application for Naturalization (N-400) fees. You must use the form G-1450, Authorization for Credit Card Transaction, fill it out and place it on top of your N-400 form when filing. There is no additional fee charged for using your credit card to pay for your N-400 fees. Note: USCIS will destroy your Form G-1450 after processing your payment, regardless if your application is accepted or rejected.
Acceptable Credit Cards: Visa, MasterCard, American Express and Discover are approved for use. You may also use gift cards with Visa, MasterCard, American Express and Discover logos.
For more detailed information about this subject please review the USCIS Web Page, “Pay Your N-400 Application Fee with Your Credit Card“.
Source of Information:
USCIS.gov, 9/17/15, Web Page: Pay Your N-400 Application Fee with Your Credit Card
USCIS.gov, 10/23/15, Web Page: N-400, Application for Naturalization
USCIS.gov, 9/17/15, Web Page: G-1450, Authorization for Credit Card Transactions