You can add the following options to First-Class Mail® (except for postcards) to…
Insure the contents.
Insurance for loss or damage up to $5,000 for merchandise only.
Registered Mail™ for loss or damage up to $25,000.
Get tracking information (parcels only).
USPS Tracking™ to see tracking updates, including date and time of delivery or attempted delivery using our Track & Confirm tool.
Signature Confirmation™ to see when the parcel was delivered or delivery was attempted, and add security by requiring a signature. Must meet additional requirements.
Get proof of mailing.
Certificate of Mailing as a way of proving the date you sent it. Must meet additional requirements.
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 email or postcard showing the recipient's signature. Must meet additional requirements. Must be combined with Certified Mail, Registered Mail, insurance (over $200), or COD service.
Get only authorized recipients to sign for the delivery.
Restricted Delivery to specify who is allowed to sign for the delivery. Must be combined with Certified Mail, Registered Mail, Insured Mail (over $200), or COD service.
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 for business mailings ›
Commercial Prices
500 is the minimum quantity to mail at commercial prices.
Requirements for Automation Discounts
- Delivery point barcodes on each piece in the address block or in the barcode clear zone.
- Address list that has been checked and CASS-certified within the last 180 days.
- Complete address with ZIP Code™ or ZIP+4® Code.
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.
- Letters 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.
- There are restrictions for mailing restricted and hazardous materials.
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.
- Large envelopes that exceed these maximum large envelope dimensions will be charged package rates.
- Maximum weight of 13 oz.
- There are restrictions for mailing restricted and hazardous materials.
Packages
- Maximum weight of 13 oz.
- Up to 108" in combined length and girth.
- There are restrictions for mailing restricted and hazardous materials.
- With few exceptions, cigarettes and smokeless tobacco shipments cannot be mailed.
See tobacco restrictions and guidelines ›
Find out what you can mail ›