The United States Postal Service plans to raise rates in August of 2021. As part of its 10-year plan, “Delivering for America,” a request for these increases was filed with the Postal Regulatory Commission on May 28. 

According to a USPS press release, the proposed Mailing Services price changes include:

ProductCurrent PricesPlanned Prices
Letters (1 oz.)55 cents58 cents
Letters additional ounce(s)20 cents20 cents (unchanged)
Letters (metered 1 oz.)51 cents53 cents
Domestic Postcards36 cents40 cents                                     
Flats (1 oz.)

Outbound International Letters
(1 oz.)
$1.00 $1.20$1.16

$1.30
Under the current pricing model and the proposed rate change, the Postal Service still has some of the lowest letter-mail postage rates in the industrialized world and continues to offer a great value in shipping.  The chart below is taken from the USPS press release.

SINGLE PIECE LETTER-MAIL POSTAGE RATES, INTERNATIONAL