Buying USPS postage online is a convenient way to skip the post office line and often access lower rates. In 2026, the process depends on whether you are sending a standard letter or a package, as the "First-Class Package Service" has been replaced by USPS Ground Advantage . Buying Postage for Letters and Envelopes
You can buy standard postage online primarily in the form of stamps or through specialized third-party services. USPS Ground Advantage