What Is a Certificate of Mailing?

Doug Morrow, ConnectSuite Director of Postal Relations
Updated July 14, 2022
4 min read

Of the variety of extra services the USPS offers for different mailing needs, Certificate of Mailing is one of the easiest to understand and use. This article will clarify what a Certificate of Mailing is, when it’s used, how much it costs, and how easy it is to send mail with it yourself!

What is a Certificate of Mailing?

Certificate of Mailing is an extra service that can be used with a number of mail classes, including First-Class and Priority Mail. This extra service is super simple because it only does one thing! It shows that you sent your mail piece when you say you did.

As a more complete definition, a Certificate of Mailing is a receipt that provides evidence that a mail piece has been presented to the USPS for mailing. It is an official record that includes the date your mail piece was accepted by the USPS.

A Certificate of Mailing does not provide a record of delivery, and the USPS does not retain a copy of the receipt. Therefore, it is crucial that you hold onto your own copy.

The Two Types of Certificates of Mailing: PS Form 3817 and PS Form 3665

There are two types of Certificates of Mailing: PS Form 3817 and PS Form 3665.

The 3817 is used when just one or two pieces are being mailed. A 3817 is filled out for each piece that is being mailed.

The 3665 can be used when sending one or two pieces, though it is most frequently used when three or more pieces are being mailed at the same time. Each piece is listed on the 3665.

PS Form 3817
PS Form 3665

When is it used?

Certificate of Mailing is used when you simply need evidence that a mail piece was presented to the USPS for mailing on a certain day. If your mail piece is lost, damaged, or encounters some other problem in the mail stream, you can produce your receipt to prove your piece entered the mail stream on a certain day. However, you will not be able to prove that piece actually made it to its destination.

A Certificate of Mailing is most commonly used for time-sensitive legal or financial documents, including…

  • Tax forms
  • Documents for legal proceedings
  • Government forms
  • Checks

How much does it cost?

The Certificate of Mailing extra service costs $1.75 for a single piece and $0.50 per piece when sending three or more pieces with PS Form 3665. These fees are in addition to the cost of postage.

How do I send mail with Certificate of Mailing?

Since it’s a relatively simple extra service, sending mail with a Certificate of Mailing is pretty straightforward.

Step 1: Collect the appropriate postal form (3817 or 3665) from the window clerk at the post office.

Step 2: Fill out the postal form with your piece information. You can find some simple instructions on page two of PS Form 3665.

Step 3: Present your mail pieces to the window clerk along with your completed form. The window clerk will postmark each form or each page of the 3665 with a round-dated stamp, and it will be returned to you to become your receipt. Be sure to hold onto it, as the USPS does not retain a copy itself.

How do I send mail with Certificate of Mailing with e-Certify?

In addition to creating certified mail, e-Certify also allows you to create mail pieces with a Certificate of Mailing. Some of the benefits include…

  • No forms to fill out manually
  • Validate recipient addresses to ensure USPS compliant formatting
  • Eliminate human error and save time

Step 1: Create your mail piece by selecting a mailing profile, entering a recipient address, and selecting a page count. Note that Certificate of Mailing cannot be combined with any other extra service offered in e-Certify. If you have many pieces to create, use the file upload for batch piece creation.

Step 2: Print the banner page for your piece and the completed PS Form 3665. Insert the banner page into a window envelope along with the item you’re mailing.

Step 3: Bring the 3665 and your mail pieces to the post office. The window clerk will postmark each page of the 3665 with a round-dated stamp, and it will be returned to you to become your receipt.

About Doug Morrow

Doug was employed by the USPS for 32 years before becoming the Director of Postal Relations with ConnectSuite. During his time with the USPS, Doug gained experience in 10 different positions, worked with three districts, and became an expert by learning the intricacies of USPS processes, protocols, and systems. He began his career as a PTF clerk and worked at the window at multiple post offices in Minnesota. As he advanced to new positions, Doug quickly became interested in mail automation, computers, and computer language, recognizing opportunities to streamline and advance processes for sorting and delivering mail. After successfully implementing new automation in offices within Minnesota, Doug went on to carry out many similar projects for offices across the midwest.

In addition to his prowess for learning the details of high-level processes and formulating automation for the necessary pieces, Doug’s success in the field is largely attributed to his ability to understand people, work with them, and earn their trust. During his time as an Operational Support Specialist, Manager of Mail Processing, and Manager of Operations Support, Doug trained countless employees and was responsible for explaining complex problems and solutions.

After working as the Postmaster for the Sioux Falls post office for some time, Doug spent the last 6 years of his career with the USPS as District Manager of the Hawkeye District where he oversaw around 10,000 employees across hundreds of offices.

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