Filling out the FAFSA will be one of the most important things you do when seeking out need based financial aid. Many scholarships that are need-based may ask you to provide some proof of financial need, which at times may be the FAFSA, but also might need to be proven through other documents, such as a tax return. If you can’t prove that you have a real need for financial help, you will likely not be eligible for some scholarships and grants.