You’ve prepared your mail pieces, the appropriate postage has been applied, and all you have left to do is enter them into the mail stream. When you’re mailing pieces with the USPS, there are a number of ways to do this.
If you’re a household mailer sending simple First-Class letters, you might just leave them in your mailbox with the flag up or drop them into a blue collection box somewhere.
However, if you’re mailing important documents for your firm with extra services like Certified Mail, you’ll likely want definitive proof that your pieces successfully made it into the mail stream, leaving nothing to chance. After all, there could be legal consequences if any one of those pieces doesn’t make it to the intended recipient, and you won’t want to be held responsible. This speaks to the importance of proof of acceptance, and that is where PS Form 3877 comes into play.
What is PS Form 3877?
PS Form 3877, also known as the Firm Mailing Book for Accountable Mail, is used when three or more pieces with extra services are presented for mailing at one time. It is most commonly used with certified mail pieces. The 3877 lists each mail piece that is being sent as well as some basic information about each piece, including the recipient address, tracking number, extra services selected, and the appropriate fees for the piece. Rather than having to generate individual mailing receipts for each article in the mailing, the 3877 compiles them all onto one form that becomes the mailer’s single receipt for all the pieces.
Here’s how it works. The mailer compiles all of his pieces along with a completed 3877 and brings them to the post office. When presented to the window clerk, the clerk approves and postmarks the 3877 with a round-dated stamp. It is then returned to the mailer as proof of acceptance. This is what the form looks like:
Why should I use one?
But why go through the hassle of bringing your pieces to the post office and getting the 3877 stamped? Couldn’t you just drop them in a blue collection box, dust off your hands, and walk away?
Yes, you could. And your pieces would probably make it into the mail stream, receive an acceptance scan, and make their way to their destination. However, when dealing with critical business communications, such as legal notices, debt collections, or health care records, you don’t want to leave that to chance. And you don’t have to. Getting the 3877 stamped at the post office ensures you are able to hold the USPS accountable for your mail pieces. So, if any of your pieces are lost, damaged, or encounter some other problem in the mail stream, you can produce your 3877 as a receipt that proves the piece was accepted by the USPS.
When you’re sending certified mail, a receipt is included in the fee for the extra service. When using the traditional hardcopy forms for Certified Mail, PS Form 3800 is stamped and returned to the mailer as the receipt. However, generating these mailing receipts for each piece in a large batch would be cumbersome and tedious. As described, the 3877 acts as the replacement for all those forms. Without it, you’re simply not leveraging the full capability of Certified Mail.
What about the proof of acceptance PDF I get from e-Certify?
When you create mail pieces in e-Certify, you can choose to receive an email notification with a proof of acceptance (POA) document attached when your piece receives its first scan from the USPS. You can see an example of a POA here.
This document is generated by ConnectSuite and simply informs you when your piece receives its first scan from the USPS. While this POA document acts as a helpful notification for the mailer, it’s not a detailed receipt, and it’s not a replacement for the 3877. Relying on the POA document as your sole form of proof of acceptance assumes that every one of your mail pieces will receive its first scan without any issues. Unfortunately, this is sometimes not the case.
Claims made by other digital solutions for certified mail often complicate this topic. Many go as far as to say that the POA document they provide will allow you to ‘skip the trip to the post office’ and act as your one and only form of proof of acceptance. Messages like these should be taken with extreme caution. They fail to mention that you’re also giving up your receipt for your important certified mail pieces in the process.
Can you skip the trip to the post office? Yes, you can. But you’ll also be giving up the best form of evidence and assurance that the USPS took possession of your mail pieces. This is crucial if something happens to them in the mail stream.
How do I use a 3877 with e-Certify?
Fortunately, e-Certify makes the whole process of using a 3877 as easy as it gets. e-Certify eliminates the need to fill out the form by hand by providing you with a digital copy that’s complete with all your piece information. Here’s all you need to do:
Step 1: After submitting your selected mail pieces to the USPS from your Mail Queue, you will be taken to a confirmation page. From there, you can print the completed 3877 or 5630 for your mail pieces by clicking the icons on the right.
Step 2: Bring your 3877 along with your mail pieces to the post office and present them to the window clerk. After approval, the clerk will postmark the 3877 with a round-dated stamp. It will then be returned to you as proof of acceptance.
Can PS Form 5630 be used in place of PS Form 3877?
In short, no. It is better to think of PS Form 5630 as an enhancement that offers additional features. It is not a replacement for PS Form 3877.
PS Form 5630, also known as the SCAN Form, features a single master barcode that represents all articles in the mailing. Once that single barcode is scanned by the window clerk, all associated pieces receive an “Acceptance” event from the USPS.
The 5630 is very helpful for mailers that send large batches of pieces, as it ensures every piece in the mailing receives an “Acceptance” event right away. However, it is important to note that the USPS employee is not required to count the articles included in the mailing for verification, and the form does not receive a round-dated stamp. It also does not list piece information in detail like the 3877.
For these reasons, the 5630 does not act as a replacement for the 3877. Though, when used in conjunction with the 3877, it does offer an additional benefit. That is, in addition to having the 3877 as evidence that the USPS took possession of your piece, the piece is sure to have an “Acceptance” event recorded in the USPS database.
Whether you use the 3877 along with the 5630 or just the 3877, you’ll rest easy knowing your business critical mail is fully accounted for.

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.
Read More

Doug Morrow
September 2, 2021 · 6 min read

Doug Morrow
September 2, 2021 · 4 min read

Doug Morrow
September 2, 2021 · 7 min read