The current 42-cent postage stamps are good through May 10. "Forever" stamps last, well, forever.

For the third time in as many years, the U.S. Postal Service is raising its first-class mail rate, this time to 44 cents. The increase takes effect May 11.

Postal Service spokesman David Partenheimer said the increase will cost the average household an additional $3 over the course of a year.

"If you compare that with some other prices that are going up -- utility costs, food prices -- that's a very reasonable increase," he said. "As a business, we're in the same situation as American families and other businesses.

"Our mail volume has been going down as businesses and people in general mail less, so we're kind of in the same boat as everyone else."

Anne Berger, Cumming postmaster, said the branch will stock up on "forever" stamps prior to the increase.

The stamps are sold at the current rate, but can be used for sending mail regardless of the rate. For example, customers who purchase the stamps before the increase will pay 42 cents, but can mail their packages after May 11 without having to add 2-cent stamps.

While forever stamps are not a new concept, Berger said many customers prefer to add 1- or 2-cent stamps to their current commemorative stamps.

"People won't stock up on forever stamps, they stock up on penny stamps," she said. "Sometimes it's more important how an envelope may look, especially in the case of a wedding."

For $1, customers can purchase a roll of 100 1-cent stamps, even if they don't have that many 42-cent stamps, Berger said.

The upcoming increase probably won't be the last, Partenheimer said.

Since the Postal Accountability and Enhancement Act of December 2006, postal rates are checked and adjusted on an annual basis.

Changes are capped at the rate of inflation, or 3.8 percent for this year, Partenheimer said. If there's no inflation, or if there's deflation, prices may stay the same.

In years past, postage rates would increase by larger amounts but on a less frequent basis, Partenheimer said.

"While we have more frequent changes now, they're generally smaller than in the past," he said. "Our new pricing system enables customers, especially our business customers, to budget and plan for these price changes well in advance."

To help with the transition, customers can order stamps online, or through the mail. Both options, Berger said, are a "good way for customers to get their stamps without having to wait in line."