You can add the following options to all First-Class Mail® (except for postcards) to…
Insure the contents.
Insurance coverage up to $5,000.
Registered Mail™ for loss or damage up to $25,000.
Get delivery information.
Delivery Confirmation™ (packages only) to see when it was delivered or delivery was attempted.
Signature Confirmation™ (packages only) to see when it was delivered or delivery was attempted, and add security by requiring a signature.
Get proof of mailing.
Certificate of Mailing as a way of proving the date you sent it.
Get proof of mailing and delivery information.
Certified Mail™ See when it was delivered or delivery was attempted. Requires the signature of the recipient.
Get proof of delivery.
Return Receipt with proof of delivery sent by mail or email showing the recipient's signature.
Get only authorized recipients to sign for the delivery.
Restricted Delivery to specify who is allowed to sign for the delivery.
Get your customers to pay for merchandise.
Collect on Delivery (COD) Recipient pays for merchandise and shipping when they receive the package.
Send contents needing extra care.
Special Handling to get preferential handling.
Learn more about extra services ›
Postcards
- Must be rectangular.
- Minimum size of 5" long x 3 1/2" high x 0.007” thick.
- Maximum size is 6" long x 4 1/4" high x 0.016” thick.
- Postcards over 6" long x 4 1/4" high x 0.016" thick will be charged as a letter or large envelope, depending on size.
Letters
- Must be rectangular.
- Minimum size is 5" long x 3 1/2" high x 0.007” thick.
- Maximum size of 11 1/2" long x 6 1/8" high x 1/4” thick.
- Maximum weight is 3.5 oz.
- A letter will be charged a nonmachinable surcharge if it’s a square letter 5" x 5" or larger, it doesn’t bend easily, has clasps or similar closure devices, has an address parallel to the shorter dimension of the letter, is lumpy, or the length divided by height is less than 1.3 or more than 2.5.
- Most hazardous materials cannot be shipped.
Large Envelopes
- Must be rectangular.
- Minimum size is either more than 11 1/2" long x 6 1/8" high or 1/4" thick.
- Maximum size of 15" long x 12" high x 3/4” thick.
- Maximum weight of 13 oz.
- Large envelopes that exceed these dimensions will be charged package rates.
- Most hazardous materials cannot be shipped.
Packages
- Maximum weight of 13 oz.
- Up to 108" in combined length and girth.
- Most hazardous materials cannot be shipped.
- With few exceptions, cigarettes and smokeless tobacco shipments cannot be mailed.
See tobacco restrictions and guidelines ›
Find out what you can mail ›
