While you may have submitted your college applications, you aren’t quite finished with the process yet. If you’ll be applying for financial aid, now is the time to fill out the application. While many families have a pretty good idea of the process, there’s one mistake students and their parents often make: They wait too long to file. That can mean the difference between collecting and missing out on thousands of dollars in financial aid.

Why does it matter? Because the Free Application for Federal Student Aid (FAFSA) isn’t just the gateway for money from the federal government. States, colleges, and many scholarship programs use FAFSA to determine eligibility for financial aid and many have much earlier deadlines or give out money on a first-come, first-served basis. Even some federal aid, such as campus-based work-study programs, is based on when you apply.

“The sooner you file the more money you’re likely to get,” says Mark Kantrowitz, publisher and vice president of strategy for Cappex.com, a website that helps students find financial aid for college. According to Kantrowitz’s analysis, students who file the FAFSA by the end of March get twice as much grant funding as students who file later.

Ten states award money on a first-come, first-served basis, three have deadlines in February, and a dozen have deadlines in early March, according to Edvisors, a network of free websites that help students plan and pay for college. You can check Edvisors site for the 2016-2017 FAFSA deadlines by state. For school deadlines, contact the colleges you are applying to directly.

Changes Are Coming

You can file the FAFSA for the 2016-2017 school year anytime from January 1, 2016, up through June 30, 2017, which allows you to apply for aid even once you're in school. There are more than 100 questions and you’ll need information from your 2015 taxes. But you don’t have to wait until you have filed your return. You can estimate the information you need based on your 2014 taxes and update it later after you file.

There are some important changes to the FAFSA this year that will improve the process, says David Levy, editor of Edvisors. One is that steps have been taken to keep your information more confidential than in the past.

When you fill out the FAFSA, you can list up to 10 colleges to receive your financial information. Starting with this FAFSA season, the Department of Education (DOE) no longer gives colleges access to this list. The reason: Some organizations, such as the National Association for College Admissions Counseling, voiced concerns that some colleges used the list, which typically corresponds to the order of a student’s preferred college, to determine admission decisions and even how much aid to give.

Looking ahead, the other change is that for the 2017-2018 school year, you will be able to file the FAFSA even earlier than in the past. Up until now, the earliest you could apply for financial aid was January 1 of the year you planned to start college.

Now you’ll be able to file the application as early as October 1 the year before you start college. Because applications will now be accepted earlier, you’ll be able to apply based on the information you provided in your 2015 tax return. If you file the FAFSA application online you can use a tool that imports data from your return, which will reduce errors that can hold up processing, says Kantrowitz. Check the Department of Education (DOE) website for deadlines.