It may be becoming more common for students and their families to pay for tuition costs with a credit card, but that doesn’t mean you should skip the fine print.

Throughout the United States, approximately 85% of large colleges and universities permit tuition payments to be made with a credit card, but 57% of those schools add on a service fee of around 2.62%. When you’re dealing with the increasingly high cost of higher education, that seemingly insignificant percentage can suddenly become enormous.

Some schools state that the service charge covers the university’s cost for processing and rates are supposedly set by outside companies. With the popularity of online billing and outsourced billing on the rise, certain institutions may not want to take responsibility for implementing these costs. And although outsourced billing means that invoices are delivered quickly and accurately, online billing can make these charges easy for families to miss.

The usage of these fees varies across the higher educational system. For instance, DePaul University accepts credit card payments without the added fee, but Columbia College Chicago, Loyola University Chicago, Northwestern University, and the University of Illinois at Chicago all charge an additional fee, ranging anywhere from 2.4 to 2.75%.

Despite the fact that most of the major colleges and universities in the Chicago area charge these fees, 89% of the largest community colleges throughout the country do not. It begs the question as to whether higher regarded schools are making subtle moves to exclude students who are less financially secure.

With student loan debts mounting, most families cannot afford to pay additional credit card processing fees on top of staggering tuition costs.

Although it represents a convenient, easy way to pay tuition fees, families are being urged to think wisely before using a credit card for college payments. Whether you receive your bill electronically or on paper, be sure to read the fine print and make the choice that makes the most sense for your financial situation.