The cost of mailing a first-class letter will go up by a penny in January.

The Postal Regulatory Commission on Friday approved the proposed rate increase, which raises the price of a first-class domestic stamp to 46 cents.

The price of a postcard will increase from 32 cents to 33 cents, while a new global "forever" stamp will allow customers to mail letters anywhere in the world for one set price of $1.10. Currently, the prices for international letters vary.

The prices go into effect Jan. 27.

The U.S. Postal Service, which posted a record annual loss of $15.9 billion, proposed the rate increase last month.

The rate increase is tied to the rate of overall inflation. It will make only a small dent in the mail agency's financial losses.