First-Class Mail & Postage | USPS

First-Class Mail & Postage | USPS First-Class Mail service is an affordable and easy way to send envelopes and postcards. First-Class Mail Forever stamps cost $0.82 (the current 1 oz price) and will never expire, even if the First-Class postage rate goes up. To send packages, see USPS Ground Advantage service. Features & Pricing: - Mail delivered in 1–5 days - Our best-priced service for items up to 13 oz - One price for up to 3.5 ounces with commercially priced letters and cards - Prices based on shape and weight Postmarking & Proof of Mailing: If you want to ensure that your mail receives a postmark on the day you mail it, ask a retail associate at a Post Office retail counter to hand-cancel it for free. To get an official record that you sent an item on a specific date, you can pay an extra service fee for a Certificate of Mailing. First-Class Mail items are eligible for Delivery Confirmation services such as Certified Mail. Standard Letter & Postcard Sizes: - Letters: Standard-sized, rectangular envelope stamps start at $0.82. Square, oversized, or unusually shaped envelope stamps start at $1.31. - Postcards: Standard-sized, rectangular postcard stamps start at $0.65. Oversized postcards need letter stamps, which start at $0.82. - Large Envelopes: Large envelopes (flats) start at $1.69. Weight, Size, & Shape Requirements: Maximum weight for First-Class Mail letters is 3.5 oz; for large First-Class Mail envelopes, the maximum weight is 13 oz. All postcards and envelopes must be rectangular, otherwise an additional charge may apply. Additional size restrictions apply depending on the type of mailpiece. Additional Charges for Irregular Mailpieces & Envelopes: - Nonmachinable Envelopes: Unusually shaped mail, like square or vertical envelopes, lumpy envelopes, rigid envelopes, and mail with clasps, string, or buttons, must be hand-canceled and are charged a nonmachinable surcharge. - Large Mailpieces: Letters exceeding standard envelope maximum dimensions are charged large envelope (flat) prices. - Large Envelopes Treated as Small Packages: Large First-Class envelopes exceeding maximum dimensions or that are rigid, non-rectangular, or not uniformly thick are charged package prices and shipped with USPS Ground Advantage. For Businesses: USPS offers commercial pricing and automation discounts. First-Class Mail commercial pricing is available for presorted letters and flats with a minimum quantity of 500 mailpieces. Bulk discounts and automation discounts may apply.