postalref

Certificate of Mailing

A Certificate of Mailing is a USPS form that gives a mailer evidence that its mailpieces were presented to USPS for mailing. USPS postmarks the form when the mail is presented and returns it to the mailer as a receipt. It is not a record of delivery, and USPS keeps no copy.

Updated October 28, 202629 sources

What it is

A Certificate of Mailing is a receipt the mailer fills in and USPS postmarks. It shows the names and addresses of the sender and each addressee, and it may show the postage paid. The mailer may add its own invoice or order numbers as a reference.

The service comes on several forms, chosen by how many pieces the mailer presents:

  • Form 3817, for fewer than three individual pieces presented at a retail Post Office, station or branch.
  • Form 3665, the firm sheet, for three or more pieces.
  • Form 3606-D, the Certificate of Bulk Mailing, which states only the number of identical-weight pieces mailed.
  • Form 3877, the Firm Mailing Book, a bound book of sheets for listing accountable mail such as Certified Mail.

Form 3877 is not technically a Certificate of Mailing form, though it uploads the same way. The book replaces a separate mailing receipt for each article. Certificate of Mailing pieces go on Form 3665 or Form 3606-D instead. e-Certify, a tool for creating, tracking and managing Certified Mail, provides a completed Form 3877. A window clerk postmarks it and returns it as proof of acceptance.

Form 3606-D gives no evidence that a piece went to a particular address.

A certificate is the official record of the date USPS accepted a mailing, and only that. It is not proof of delivery or of mailing, and it does not insure the items against loss.

How it works

On paper, the mailer brings the completed form with the mail, since a certificate may be presented only at the time of mailing. USPS postmarks each Form 3817 or each sheet of a Form 3665 and returns it to the mailer as a receipt.

Forms 3606-D, 3665 and 3877 can also be uploaded. They go to PostalOne!, the USPS system that links a customer's mailing information to business mail acceptance. Mailers who prefer the paper process may keep using it.

A clerk at a business mail entry unit verifies each upload. That unit is the USPS organization that receives, verifies and accepts business mail.

An electronic Certificate of Mailing, from upload to receipt.

  1. The mailer uploads the form data to PostalOne! and receives a transaction ID and receipt barcode.
  2. A business mail entry unit clerk finds the form by that ID or barcode and verifies it.
  3. PostalOne! charges the fee to a permit linked to the mailer's Enterprise Payment System account.
  4. PostalOne! generates the round-stamped PDF of the form.
  5. The mailer receives the PDF through the Mail.dat client or downloads it from the Business Customer Gateway.

Submitting electronically

Before a first upload, the mailer sets up a Business Customer Gateway account and an Enterprise Payment System account. Jobs go in through Postal Wizard, a web-based tool, or through Mail.dat, which needs presort software.

The electronic forms accept domestic and international sender addresses, but only domestic addressees. The upload has no link to the mailing's postage statements, so the mailer brings the job's identifier to the clerk at acceptance.

Uploading through Postal Wizard

Postal Wizard takes each form as an Excel workbook built from a USPS template. The workbook's sheet name includes the form number, such as 3665.

  1. In the Business Customer Gateway, open Postal Wizard, then Certificate of Mailing.
  2. Download the template for Form 3606-D, Form 3665 or Form 3877.
  3. Fill in the template, completing every asterisked field.
  4. Select Upload Certificate of Mailing and enter the location, permit type and permit number.
  5. Upload the form through the permit's Permit/Pub link.
  6. Keep the receipt, because the business mail entry unit needs its Unique COM ID to verify the job.
  7. After the clerk approves the job, download its round-stamped PDF from the Certificate of Mailing Report.

Until a clerk approves the job, its Transaction Status reads Pending. On Form 3606-D, the Class of Mail field takes a two-character code, such as FC for First-Class Mail.

On the Form 3877 template, sender and addressee names are limited to 60 characters. Each type of mail or service a piece uses must be marked Y.

Uploading through Mail.dat

A Mail.dat Certificate of Mailing job is prepared to the newest version of the Mail.dat Technical Specifications. It holds six files and no others: a header, a .mpa file and four Certificate of Mailing records. Its header's Presentation Category is R, for Certificate of Mailing.

FileRecordHolds
.chrCertificate of Mailing Header RecordThe type of each certificate in the job
.cdrCertificate of Mailing Detail RecordAddressees, for Form 3665 and Form 3877
.cbrCertificate of Mailing Bulk RecordThe bulk certificate, Form 3606-D
.cfrCertificate of Mailing Special Fee RecordExtra services for accountable mail, Form 3877

The Mail.dat client, the program that validates and uploads Mail.dat files to PostalOne!, sends the job. The client is set up with batch mode and a directory for PDFs. Enhanced-XML is the only receipt the Mail.dat client supports for these jobs.

Forms 3606-D and 3665 through the Mail.dat client.

  1. In Job Validation/Upload, select Add Job.
  2. Choose the job's files to upload.
  3. Validate the job only, or validate and upload it.
  4. Accept the agreement for job validation and upload.
  5. Start the Receipt Poller to see the job's submissions.
  6. A business mail entry unit clerk searches the receipt barcode and approves or rejects the job.
  7. Download the PDFs by giving the receipt barcode to the client's batch script.

The receipt barcode is a system-generated string of text in the Mail.dat receipt, which the mailer brings to the business mail entry unit for verification. Each job gets its own, such as 00000187. A search for a Mail.dat job's receipt barcode keeps its leading zeros.

In a receipt event, a <com-loaded-result> of P shows that the job passed. For Form 3665, each <com-record-page-info> is one piece, with its barcode, fee and page in the PDF. After approval, a second Receipt Poller run shows the job as paid, with its fee and the Enterprise Payment System account charged.

Fees

Each article on Form 3817 or listed on Form 3665 pays a Certificate of Mailing fee on top of postage, and so does each duplicate copy. The fee differs for an individual article and for an article with a firm mailing book. Notice 123 gives the prices.

An electronic job pays through a permit linked to an Enterprise Payment System account, and the fee is deducted once the clerk approves it. The account needs enough funds before a job is uploaded. That payment covers only the certificate, and postage is paid separately. Form 3877 carries no Certificate of Mailing fee.

Extra service fees are paid outside the electronic process. Certified Mail fees, for example, go on a postage statement or a meter strip on the mailpiece.

Rules

Certificates of Mailing provide evidence that individual mailpieces have been presented to the USPS for mailing and may be presented only at the time of mailing.

A mailer may present a certificate only at the time the pieces it covers are mailed.

The Form 3606-D cannot be used as a Certificate of Mailing of individual mailpieces or itemized lists.

Form 3606-D cannot serve as a certificate for individual pieces or for an itemized list.

Mailers must obliterate all unused portions of the addressee column with a diagonal line.

The mailer must draw a diagonal line through every unused part of the addressee column.

Alterations must be initialed by the mailer and acceptance employee.

Any change to the form must carry the initials of both the mailer and the USPS acceptance employee.

A Certificate of Mailing form must be completed by the mailer and all entries must be typed or printed in ink, by ballpoint pen, or computer-generated.

The mailer must fill in the form, and every entry must be typed, printed in ink by ballpoint pen, or generated by computer.

Mailings of fewer than 50 pieces and less than 50 pounds of corresponding articles presented at one time must be presented to a retail Post Office, station, or branch.

A mailing under 50 pieces and under 50 pounds must be presented at a retail Post Office, station or branch.

Mailings of at least 50 pieces or 50 pounds of corresponding articles presented at one time must be presented to a Post Office business-mail entry unit (BMEU) or authorized detached mail unit (DMU).

A mailing of 50 or more pieces, or 50 or more pounds, must be presented at a business mail entry unit or an authorized detached mail unit.

Mailers must upload the electronic PS Form 3606-D, Certificate of Bulk Mailing – Domestic, before presenting the mailing at the BMEU for processing.

A mailer using the electronic Form 3606-D must upload it before presenting the mailing at the business mail entry unit.

What goes wrong

A Form 3665 job with one or two pieces is rejected, because the form needs at least three. Postal Wizard checks each upload and returns these common errors:

ErrorFix
Processing Error – [xxx] is requiredComplete every asterisked field.
Processing Error - Cannot get a NUMERIC value from a STRING cell - Date ValueFormat the cell as a date in Excel.
Processing Error - Verification Facility ZIP Code not found - String ValueEnter a valid 5-digit or 9-digit ZIP Code.
Processing Error - Error saving upload Inserted value too large for columnKeep the field within its character limit.
Processing Error - Invalid Class of Mail (see instructions sheet) - String ValueUse the two-letter Class of Mail abbreviation.
Processing Error - Pieces Listed by Sender does not match Mail Pieces uploadedMake the piece count on the form match the pieces listed.

USPS is not liable for storing electronic certificates, though mailers can download them from PostalOne!. USPS recommends mailers keep every PDF on a safe internal storage drive.

Terms

PS Form 3877Form 3877, Firm Book for Accountable Mail, Firm Mailing Book
a multipage bound book that contains individual sheets with space to enter multiple article numbers for accountable mail such as Certified Mail, COD, Priority Mail ® Express, and Insured Mail pieces
Certificate of Mailing - AutomationCOM automated solution, Certificate of Mailing feature in PostalOne! application
Electronic submission of Certificate of Mailing which provides evidence that mailpieces have been presented to the USPS for mailing.
PostalOne!PostalOne! system
the information management system that provides an electronic linkage between a customer’s mailing information and the Postal Service’s business mail acceptance and induction processes. It produces postage statements and supporting documentation.
Postal WizardPW, PSW, Postage Statement Wizard
a tool that provides a secure way to submit postage statements online
Mail.dat
Mail.dat is an industry-defined database structure consisting of files linked by key fields.
PostalOne! Mail.dat ClientPostalOne! Mail.dat Client Software, PostalOne! Mail.dat Client Application, Mail.dat client
is used to validate and upload Mail.dat files to the PostalOne! System.
Business Mail Entry UnitBMEU, BME, PAU, Business Mail Entry, platform acceptance unit
Business Mail Entry Unit (A specialized USPS organization responsible for receiving, verifying, and accepting business (bulk) mail)
Detached Mail UnitDMU, Delivery Mail Unit
Detached Mail Unit (A BMEU located at a mailer’s mail production plant)
Enterprise Payment SystemEPS, Electronic Payment System, EPS system, Enterprise System
allows customers to pay for Postal products and services through a single account, called the Enterprise Payment Account (EPA).

Documents

User Guides

Fact Sheets

Contacts

Questions go to the mailer's assigned business mail entry unit or the Mailing and Shipping Solutions Center. For technical issues, the center answers at MSSC@usps.gov or 1-877-672-0007, Monday through Friday, Central time, closed on holidays.

Sources