By David Shepardson

WASHINGTON The United States Postal Service (USPS) is hiking the price of first-class mail stamps to 66 cents from 63 cents effective Sunday.

This is the latest in a series of price increases to help offset inflationary pressures and declining first-class mail volumes. USPS in January boosted stamp prices to 63 cents from 60 cents. The Postal Service on Sunday is raising overall first-class mail prices by 5.4% after the Postal Regulatory Commission gave approval.

Stamp prices are up 32% since early 2019 when they rose from 50 cents to 55 cents. USPS said Friday "these price adjustments are needed to provide the Postal Service with much needed revenue." First-class mail volume fell 3% last year to the lowest number in 50 years and is down 51% since 2006.

First-class mail, used by most people to send letters and pay bills, is the highest revenue-generating mail class, accounting for $24.2 billion, or 31%, of the $78.8 billion in total USPS revenue in 2022.

In April, USPS cut projected losses through 2031 by more than half after winning financial relief from Congress, instituting regular price hikes and adopting reforms.

USPS is raising stamp prices twice yearly and expects its "new pricing policy to generate $44 billion in additional revenue" by 2031.

President Joe Biden signed legislation in April 2022 providing USPS with $48 billion in financial relief over a decade and required its future retirees to enroll in a government health insurance plan.

USPS has asked the Biden administration for accounting changes for retirement contributions that would eliminate amortization payments and save USPS $2 to $3 billion per year and up to $34.6 billion over 10 years.

(Reporting by David Shepardson; Editing by Chizu Nomiyama)