What does USPS Certified Mail prove?

Certified Mail gives you a mailing receipt, a tracking number, and a USPS record that the letter was delivered or that delivery was attempted. USPS keeps the delivery record, including the recipient's signature.

What does a return receipt add?

A return receipt sends the proof of delivery to you: the signature of the person who accepted the letter and the date. It comes as a mailed green card (PS Form 3811) or as an electronic copy.

Is a Certificate of Mailing the same as Certified Mail?

No. A Certificate of Mailing proves only that you mailed something on a given date. It has no tracking and no delivery record.

Certified Mail and return receipts: what each one proves

When a letter starts a clock or settles an argument, you want to show two things: that you sent it, and that they got it. USPS sells those as separate pieces.

What Certified Mail gives you

A mailing receipt with the date you sent it.
A tracking number you can look up.
A USPS record that the letter was delivered, or that delivery was attempted. USPS keeps the recipient's signature on file.

Certified Mail is an add-on to First-Class Mail and Priority Mail. It does not make the letter travel faster.

What a return receipt adds

Certified Mail alone leaves the signature with USPS. A return receipt sends that proof to you, showing who signed and when. It comes in two forms:

Green card (PS Form 3811): a postcard attached to the envelope, signed at delivery and mailed back to you.
Electronic return receipt: the same signature and date, delivered as a file. It costs less and can't get lost on the way back.

For most disputes the electronic version is enough. Check whether a contract, lease or statute asks for a specific form before you choose.

What it does not prove

A return receipt proves an envelope was delivered and signed for. It does not prove what was inside. Keep an exact copy of the letter with the receipt, and put the tracking number in the letter itself so the two can be matched.

A Certificate of Mailing is a different, cheaper product. It proves only that you mailed something on a date, with no tracking and no delivery record.

When to send a letter certified

Notices to a landlord about repairs, deposits or ending a lease.
Demand letters and billing disputes.
Cancellations where the company has ignored other channels.
Records requests and anything with a response deadline.
Any time a contract or law says notice must be sent by certified mail.

USPS fees change every year; the current price list is on usps.com.

Sending one without a trip to the post office

We are building a connector that lets Claude or ChatGPT mail a PDF by Certified Mail and hand back the tracking number and return receipt in the chat.

See how it works

Faxing a health insurance appeal instead? Read how to fax an appeal and prove they got it.