If you’ve applied for college, and filled out an application for financial aid, you might be waiting to see how much money you’re going to get. But what if your financial aid offer isn’t what you expected? Can you ask for more money? The short answer is yes, but it will depend on a few important factors.

Most financial aid award letters will be mailed out in late March or early April. And then you’ll have until May 1 to accept or decline the offer. Within that month you can file an appeal.

First step: Contact your school

The first step is to contact the financial aid officer at your prospective school and ask about their specific guidelines for having a financial aid package reconsidered or appealed. Some schools also post this information online. Every school has their own set of rules, so it’s important to take the time to figure them out. With that said, most appeals will either have to be need-based or merit-based.

Need-based appeal

A need-based appeal stands a better chance of getting accepted if there was a significant change in your family’s financial situation. Causes fitting under this category might include loss of job, death of a parent, significant medical expenses, expenses from disasters not covered by insurance, real losses of property, eldercare and special education needs.

If your appeal is based on your financial situation, and you want more federal grants or work-study-based funding, you may be asked to fill out an appeals form and provide a cover letter detailing your situation to the financial aid office. According to Susan McCrackin, senior director of financial aid services at The College Board, this is the time to make your case.

“The more the family can share about their situation and how it will impact their ability to meet their financial responsibilities, the better the aid officer will be able to determine if the current situation warrants a change in the aid package.” McCrackin told Yahoo Finance. “Don’t be embarrassed, withholding information will only hurt the family.”

The next step is to support your case. Along with the cover letter, you should gather every document that will back up your claims — including receipts, pay stubs, medical bills, severance letters. Try your best to supply proof for any financial claims you make in the cover letter.

Merit-based appeal

If a school has offered you a scholarship based on your academic achievements, that merit-based scholarship can also be negotiated.

Like the need-based appeal, you will need to provide a letter detailing why you need more money. This is also a great place to highlight any new and higher standardized test scores or an improved GPA. Additionally, most schools will require you to provide documentation to support any financial claims you make in the cover letter — this includes receipts, pay stubs, medical bills, and severance letters.