Citing “inflationary pressures on operating expenses,” the Postal Service said in a statement that the price increases are needed for future financial stability and because “the effects of a previously defective pricing model are still being felt.”

The U.S. post office is an independent federal service that is mandated to be self-financing. It typically receives no tax money.

The proposed changes first would have to be approved by Postal Service governors.

Under the USPS proposal, the changes would mean that a 1-ounce letter that now costs 66 cents to mail would cost 68 cents. Letters up to 1 ounce that now cost 63 cents to mail would cost 64 cents, if the changes are approved.

Domestic postcard mailings would rise to 53 cents; international postcards would cost $1.55 to send. And an international letter that now costs $1.50 to mail would cost a nickel more next year if the proposed changes take effect.

According to Friday’s statement, the Postal Service also is requesting price adjustments for its so-called Special Services products, which include Certified Mail, post office box rental fees, money order fees and the cost of postal insurance.

The Postal Regulatory Commission will review the proposal before any changes can be made.

The complete Postal Service price filing, with prices for its products, is posted online.