When it comes to stamps, the word "forever" on first-class mail doesn't apply to prices.

The U.S. Postal Service is signaling that the price of a First-Class Mail Forever stamp will increase to 73 cents on July 14, 2024, up by a nickel from the 68 cents one currently costs. 

When first introduced in 2007, a Forever stamp was 41 cents. The stamps were named as such so one knew they could use the stamp "forever," regardless of when it was purchased. 

The latest proposed changes — to be reviewed and approved by the governors of the Postal Service — also include a nickel hike to the price to mail a 1-ounce metered letter, to 69 cents, the postal service said Tuesday in a news release.

Mailing a postcard domestically will run you 56 cents, a 3-cent increase, while the price of mailing postcards and letters internationally are both rising by a dime to $1.65. 

All told, the proposed changes represent a roughly 7.8% increase in the price of sending mail through the agency. 

Notably, the price of renting a Post Office Box is not going up, and USPS will reduce the cost of postal insurance 10% when mailing an item, it said. 

The cost of Forever stamps rose to 68 cents in January, from 66 cents.

The increases, part of the Postal Service's 10-year plan toward profitability, are hurting mail volume and USPS' bottom line, according to Keep US Posted, a nonprofit advocacy group of consumers, nonprofits, newspapers, greeting card publishers, magazines and catalogs.

The group called for the proposed increases to be rejected and for Congress to take a closer look at the Postal Service's operations, citing findings by NDP Analytics in March.

"If rate increases continue to proceed at this frequency and magnitude without critical review, it risks plummeting volume further and exacerbating USPS's financial challenges," according to the report commissioned by the Greeting Card Association and Association for Postal Commerce.

USPS in November reported a $6.5 billion loss for fiscal 2023, and is projecting a $6.3 billion deficit in 2024.

Kate Gibson

Kate Gibson is a reporter for CBS MoneyWatch in New York.