Washington, D.C. ? Mailing a letter will soon cost a penny more.

The cost of a first-class stamp will rise to 42 cents starting May 12, the U.S. Postal Service said Monday.

The price of the Forever stamp will go up at the same time, meaning those stamps can still be purchased for 41 cents but will remain good for first-class postage after the rate increase takes effect.

The charge for other services, such as advertising mail, periodicals, packages special services also will change. Changes in the price for Priority Mail and Express Mail will be announced later, the agency said.

Postage rates last went up in May 2007, with a first-class stamp jumping 2 cents to the current 41-cent rate.