USPS has announced that it will not be raising rates for its "market-dominated products" in 2010, ending months of speculation from businesses which had feared a rise.
Some firms had been preparing for rises of as much as ten per cent to mailing costs.
The products which will remain at their current prices include first class mail, standard mail, periodicals and single piece parcel post.
John E Potter, the postmaster general, said: "Simply stated, there will not be a price increase for market dominant products."
He added: "Many of you have expressed concerns regarding mailing costs for 2010
while increasing prices might have generated revenue for the Postal Service in the short term, the long-term effect could drive additional mail out of the system. We want mailers to continue to invest in mail to grow their business, communicate with valued customers, and maintain a strong presence in the marketplace."
Mr Potter also said that a repricing of USPS's "competitive products", which include priority mail, express mail, parcel select and many international mailing products, is currently being considered by the service.