Harvard doesn't take American Express.

And it doesn't take Visa or Mastercard either when it comes to tuition payments.

Indeed, despite a growing trend in higher education to allow students and parents to put college payments on plastic, Harvard has quietly but firmly maintained a policy prohibiting tuition payment by credit card.

The position, according to Director of Student Financial Services Nona D. Strauss reflects little more than a desire to uphold fairness and the law, and not any desire to keep customers from enjoying the benefits increasingly lavished on some card holders based on their level of purchases.

Those benefits can range anywhere from free airline tickets on U.S. air carriers to points redeemable for free dining or hotel stays.

Strauss says most of the people she comes in contact with who want to use a credit card hope to capture those benefits--to nab what could be 31,000 extra frequent-flier miles for a year of schooling or a 2 percent cash back on purchases. (Hey, $620 makes a difference.)

But allowing some people to pay by plastic would have deleterious effects on the entire student population, Strauss says. Because credit card companies charge a nominal percentage fee on every purchase, Harvard would lose a small portion of each student's tuition paid by credit, thereby forcing the College to impose a flat fee across the entire undergraduate population to recoup the losses.

Strauss says that although many of the people who want to pay by credit card are willing to absorb the fee associated with their own charges, government banking regulations prohibit the selective assessment of such fees.