WASHINGTON (AP) — The cash-strapped U.S. Postal Service is raising rates for its more profitable express mail and priority mail shipping next year, part of its efforts to stave off bankruptcy.

The new prices take effect Jan. 22 and include the introduction of a new flat rate of $39.95 for express mail boxes, with separate increases for letters. Previously, prices were $13.25 or higher based on package weight and distance.

The Post Office said the rate hikes still make its shipping the best value compared to private companies such as UPS and FedEx.

The new prices amount to a roughly 5 percent increase. They are in addition to a previously announced 1-cent hike in first-class mail to 45 cents. The independent Postal Regulatory Commission will review the proposed hikes before they take effect.