(NEXSTAR) – The price of sending a piece of mail is about to go up. The United States Postal Service is set to increase the cost of postage to cope with the rising cost of operations.

Starting Sunday, Jan. 22, the USPS plans to increase prices of some postage by 4.2%, which generally amounts to a few cents per stamp.

The cost of a Forever stamp would go up 3 cents, from 60 cents to 63 cents – the third price hike in about a year.

Forever stamps, regardless of when they are purchased, will be accepted in perpetuity – hence the name. That means if you have some already, even if you bought them at a lower price, they will still be accepted to mail letters next year and the year after that. It also means you can buy stamps in bulk now to avoid paying more after Jan. 22.

See more details on the 2023 price changes below:

ProductPrice before Jan. 22Price after Jan. 22
Letters (1 oz.)60 cents63 cents
Letters (metered 1 oz.)57 cents60 cents
Domestic Postcards44 cents48 cents
International Postcards$1.40$1.45
International Letter (1 oz.)$1.40$1.45

The USPS is also increasing the cost of sending Priority Mail by about 5.5%. Priority Mail Express will get 6.6% more expensive, and First-Class Package Service prices are set to increase by 7.8%. Priority Mail commercial rates will bump up about 3.6%.

At the same time, the cost of some Priority Mail shipping materials, including flat-rate envelopes and boxes, will go down. Using a flat-rate box or envelope lets you send a package of up to 70 pounds to any U.S. state for a flat fee.

ProductPrice before Jan. 22Price after Jan. 22
Small flat-rate box$10.40$10.20
Medium flat-rate box$17.05$17.10
Large flat-rate box$22.45$22.80
APO/FPO large flat-rate box$20.95$21.20
Regular flat-rate envelope$ 9.90$ 9.65
Legal flat-rate envelope$10.20$ 9.95
Padded flat-rate envelope$10.60$10.40

The USPS points out that most its price hikes are “well below the rate of inflation.”

The price for two other shipping services, Parcel Select Ground and USPS Connect Local, will remain unchanged, the Postal Service says.