How to Send a Letter or Postcard | USPS

How to Send a Letter or Postcard | USPS Sending a letter with USPS is easy! The service helps with most letters and postcards sent domestically (inside the U.S.), including U.S. territories and military bases in the U.S. and abroad. Step 1: Choose Envelope or Postcard Envelopes are for sending flat, flexible things, like letters, cards, checks, forms, and other paper goods. For just 1 $0.78 First-Class Mail Forever stamp, you can send 1 oz (about 4 sheets of regular, 8-1/2" x 11" paper in a rectangular envelope) to anywhere in the U.S. Envelopes must be rectangular and made of paper to qualify for letter prices. Maximum size: 11-1/2" long x 6-1/8" high. A standard No. 10 envelope is 9-1/2" long x 4-1/8" high. Contents must stay flat—no more than 1/4" thick. For letter-sized papers without folding, use a large envelope (flat); postage starts at $1.63. If the large envelope is nonrectangular, rigid, or lumpy, package prices apply. Nonmachinable envelopes (rigid, lumpy, with clasps/string/buttons, square, or vertical) require an additional $0.49. Square or vertical envelopes also cost more. Postcards are for short messages and save money at $0.61 per postcard stamp for standard-sized postcards anywhere in the U.S. Standard postcards are usually paper, 5" to 6" long, 3-1/2" to 4-1/4" high, and 0.007" to 0.016" thick. Step 2: Address Your Mail Envelopes: Write return address (sender address) in top left corner. Write delivery address (recipient address) in bottom center. Postcards: Write delivery address in the space provided on the same side as message and stamp. Address Format Tips: - Print addresses neatly in capital letters - Use pen or permanent marker - Do not use commas or periods - Include ZIP+4 Code whenever possible Write Sender Address (return address) in top-left corner: - Your full name or company name - Apartment or suite number - Full street address - City, State, and ZIP+4 Code Write Delivery Address (recipient address) in bottom center: - Recipient's full name or company name - Apartment or suite number - Full street address - City, State, and ZIP+4 Code Special U.S. Addresses: Puerto Rico: Some addresses include an urbanization or community code (URB). Example format: MS MARIA SUAREZ URB LAS GLADIOLAS 150 CALLE A SAN JUAN PR 00926-3232 U.S. Virgin Islands: Same format as standard addresses. Use abbreviation "VI": MS JOAN SMITH RR 1 BOX 6601 KINGSHILL VI 00850-9802 Military and Diplomatic Mail (APO/FPO/DPO): - Do not include city or country name for APO/FPO/DPO addresses in another country - Do include unit and box numbers if assigned: SEAMAN JOSEPH SMITH UNIT 100100 BOX 4120 FPO AP 96691 Step 3: Calculate Postage & Add Insurance or Extra Services A First-Class Mail Forever stamp costs $0.78 and goes in upper right corner (or any combination totaling $0.78). A standard postcard stamp costs $0.61. Postage depends on weight and size/shape. Weigh letters using kitchen scale, postal scale, self-service kiosk, or Post Office counter. Rule of thumb: Send 1 oz (4 sheets printer paper and business-sized envelope) for 1 First-Class Mail Forever stamp ($0.78). Large envelope (flat) postage starts at $1.63 for 1 oz. Additional Postage: - For letters up to 3.5 oz: each additional 1 oz costs $0.29 - For large envelopes up to 13 oz: price varies per additional 1 oz - Nonmachinable items cost $0.49 more - Square or vertical envelopes cost more Add-On Services (extra fees): - Certified Mail: Proof of mailing and recipient signature - Registered Mail: USPS's most secure service with manual processing, separate handling, and signatures at each step - Return Receipt: Printed or emailed delivery record with recipient's signature - Adult Signature Required: Only adults 21+ can sign with valid government ID Step 4: Send Your Mail Once addressed and postage applied, send mail by: - Putting in mailbox and raising flag - Dropping in cluster mailbox outgoing slot - Dropping in blue collection box - Taking to Post Office lobby drop Postmarks: For guaranteed postmark on mailing day, ask retail associate at Post Office counter to hand-cancel for free. Important: Envelopes with postage stamps weighing over 10 oz or thicker than 1/2" cannot go in collection boxes; must give to Post Office employee. Bonus: Sending Mail Pro Tips The Postal Service processes 425.3 million mail pieces daily using high-speed sorting machines. Stay Flexible: Postcards, letter envelopes, and large envelopes must bend through sorting machines. OK: flexible, flat items like stickers, photos, trading cards (as long as envelope stays flat, not lumpy, under 1/4" thick). Not OK: Don't put rigid objects (flash drives, coins, keys, hard plastic cases) loose in unpadded paper envelopes—use padded envelope or small box instead, sending as package. Sending Embellished Invitations: Pay extra for nonmachinable First-Class Mail, bring to Post Office counter, ask for hand-cancellation. For externally decorated invitations with wax seals, strings, ribbons, etc., put inside another envelope. Need Tracking: Tracking unavailable for First-Class Mail. For tracking, use Priority Mail Express or Priority Mail service, or add Certified Mail or Registered Mail service (can combine with Return Receipt).