The USCIS provides many of its services through its website, so applicants don’t have to visit an office for every matter related to their case. Here are some of the services provided through the site :
e-Request: Applicants can file an e-Request to find out about their application and appointment from the following section of the USCIS website. For example, if your received date was before the case inquiry date, you can inquire the reason for the delay by making a ‘case outside processing time’ inquiry. You can also inquire about missing emails and documents, correct any typographic errors, and request an appointment accommodation.
Fee Calculation: There’s a tool to help you with fee calculations for forms that have a flat fee or a varying fee. You can find out the fee by selecting you’re from a dropdown menu. If you need more information about forms and fees, including how to pay fees and refund policy, visit the filing fees section.
Online Filing: By creating a free account, you can submit your application form online. There are many forms available for online submission, including N-400, I-90, I-130, N-600, etc. Here are all the forms that can be filed through the site.
Besides these tools, there are also many resources, including a Citizenship Resources Center, N-400 early filing calculation, practice test, immigration data, and how-to guides.