Stamps Going Up a Penny It will cost 45 cents to mail a first-class letter in January By John Johnson, Newser Staff Posted Oct 18, 2011 3:33 PM CDT 6 comments Comments These are going up a penny next year, to 45 cents. (Getty Images) (Newser) – Given the dire financial straits of the Postal Service, this shouldn't be a huge surprise: The price of a stamp is going up a penny to 45 cents in January, reports the Washington Post. The first hike in more than two years is expected to pull in an extra $888 million in revenue, says the USPS. Postcards are going up 3 cents to 32 cents, though Express Mail and Priority Mail won't change. International letters will go up 7 cents to $1.05, except for Canada and Mexico letters, which will cost 85 cents.