Amazon is boosting the price of its monthly Prime membership fees for new and existing members by nearly 20 percent.

The online retailer says its annual membership fee of $99 will not change.

Starting Friday, new members will pay $12.99 a month, up from $10.99. Qualifying college students will pay $6.49 a month, up from $5.49.

Amazon.com Inc. says existing monthly members will start paying the higher fees next month.