The cost to mail a letter rose slightly Sunday when postal-rate changes went into effect, according to the U.S. Postal Service.

Stamp prices increased one cent, from 45 cents to 46 cents, to mail one-ounce letters, effective Jan. 27. The cost for letters weighing more than one ounce will stay the same, at 20 cents for each additional ounce, an announcement from the postal service says.

Postcard stamps have also seen a one-cent increase, from 32 cents to 33 cents. Letters under one ounce mailed anywhere internationally now cost $1.10, the announcement says.