USPS Form 3600-FCM is the postage statement you submit with every commercial First-Class Mail or USPS Ground Advantage mailing brought to the Post Office for acceptance. The January 2026 version is a single 10-page document covering both services, downloadable from Postal Explorer at pe.usps.com.1United States Postal Service. Postage Statement – First-Class Mail and USPS Ground Advantage Before the form is any use to you, you need a mailing permit, a funded payment account, and a mailing of at least 500 presorted pieces. Getting those in place takes longer than filling in the form, so start there.
What You Need Before the Form
Three things have to exist before Form 3600-FCM does anything for you: a permit, a way to pay, and identification numbers that tie the mailing to your business.
Mailing Permit and Annual Fee
Apply for a mailing permit at the Post Office where you plan to drop your mail. Permit imprint is the common payment method for high-volume mailers, and setting up a permit imprint account carries a one-time application fee.2USPS Postal Explorer. Mailing Permit On top of that, you pay an annual mailing fee of $370 at each Post Office where you enter commercial First-Class Mail. The fee runs 12 months and must be renewed to keep the permit active.3United States Postal Service. Notice 123 – Price List
Payment Account
Permit imprint requires an advance deposit account. You deposit funds ahead of mailing, and USPS pulls the postage when the mailing is accepted. If the balance is short, the clerk holds the mail until you top it up. No credit is extended.4United States Postal Service. DMM 604 Postage Payment Methods and Refunds These accounts now live in the Enterprise Payment System (EPS), which consolidates payment for all postal products under one account.5PostalPro. Enterprise Payment System
CRID and Permit Number
The form asks for a Customer Registration ID (CRID), a unique number identifying your business location. You get one by registering through the USPS Business Customer Gateway at gateway.usps.com, which is also where you manage permits, submit electronic postage statements, and pick up Mailer IDs.6PostalPro. Business Customer Gateway You’ll also enter your permit number and the Post Office of mailing. The permit holder’s name, address, email, and phone must match what that Post Office has on file.1United States Postal Service. Postage Statement – First-Class Mail and USPS Ground Advantage If the preparer or the mail owner is a different party from the permit holder, each gets its own section with its own CRID field.
When Form 3600-FCM Actually Applies
Commercial presort pricing requires a minimum of 500 pieces in a single mailing.7Postal Explorer. 230 Commercial Mail First-Class Mail The 500-piece floor applies to automation letters, nonautomation machinable letters, and flats alike. Below that count, you pay retail rates and Form 3600-FCM is not involved.
First-Class Mail letters can weigh up to 3.5 ounces. Flats can go up to 13 ounces. Anything heavier moves into Priority Mail with a different postage statement.8Postal Explorer. First-Class Mail Pricing on the form is shape-based, so you complete the section that matches your piece type: cards, letters, or flats.9United States Postal Service. First-Class Mail
Getting the Mailpieces to Match What You’ll Claim
Mismatched pieces are where postage statements go wrong. If you claim automation rates for pieces that fail dimensional or machinability standards, the mailing gets returned or you owe additional postage at acceptance.
Letter Dimensions
A letter-size piece must fall within these dimensions:10Postal Explorer. 100 Retail Mail Letters, Cards, Flats, and Parcels
- Length: 5 inches minimum, 11.5 inches maximum
- Height: 3.5 inches minimum, 6.125 inches maximum
- Thickness: 0.007 inches minimum (0.009 inches if over 6 inches long or 4.25 inches high), 0.25 inches maximum
- Aspect ratio: length divided by height between 1.3 and 2.5
A letter is nonmachinable, and pays a surcharge, if it falls outside the aspect ratio, is enclosed in plastic, has clasps or closure devices, contains loose items that create uneven thickness, or is too rigid to bend around an 11-inch diameter turn. Self-mailers and booklets that don’t meet preparation standards trigger the surcharge too.10Postal Explorer. 100 Retail Mail Letters, Cards, Flats, and Parcels Those pieces go in the nonautomation nonmachinable columns on the form, which carry higher per-piece rates.
Move Update
Every address on your list must have been updated within 95 days before the mailing date. This is the Move Update standard, and it applies to all commercial First-Class Mail. Approved methods include NCOALink, ACS, and other electronic address-correction tools.11United States Postal Service. DMM Revision – New Move Update Standards for First-Class Mail and Standard Mail Form 3600-FCM includes a certification that you’ve met it. If USPS finds you haven’t, you lose the commercial discount and owe full postage.
Ancillary Service Endorsements
Each piece should carry an ancillary service endorsement telling USPS what to do with undeliverable mail. The endorsement is a keyword followed by “Service Requested.” The approved keywords are Electronic, Address, Return, Change, Forwarding, and Temp-Return. Print in at least 8-point type with a quarter-inch of clear space on all sides, positioned either below the return address or above the delivery address area.12Postal Explorer. 507 Quick Service Guide
Filling In the Form
The form is 10 pages, but you only complete the pages that match your piece type and price category. It breaks into four parts: header, piece counts by presort level, postage computation, and certification.
At the top of page one, enter the Post Office of mailing, mailing date, permit number, and the number and type of containers (trays, sacks, or pallets). Federal agencies have a separate cost code field. Your EPS customer reference number goes in its box alongside your CRID.1United States Postal Service. Postage Statement – First-Class Mail and USPS Ground Advantage
The body of the form has columns for each presort level: 5-Digit, AADC, and Mixed AADC for automation letters, with parallel breakdowns for nonautomation and flat-size pieces. Enter the count at each presort level, multiply by the applicable rate, and total the section. The form has dedicated rows for per-piece rates and add-on charges like the nonmachinable surcharge.
Piece-count accuracy is where most problems start. If the reported count doesn’t match the physical mail, the BMEU clerk requires either a corrected postage statement or additional postage.13USPS. Business Mail 101 – At the Post Office Count twice before you load the trays.
2026 Commercial Presort Rates
USPS did not raise mailing service prices in January 2026, so the July 2025 rates still apply. Commercial First-Class automation letters up to 3.5 ounces run from $0.593 at the 5-Digit presort level to $0.672 at Mixed AADC. Nonautomation machinable letters run from $0.644 (AADC) to $0.686 (Mixed AADC). Nonautomation nonmachinable letters cost more, from $0.813 at 5-Digit to $1.088 at Mixed ADC.3United States Postal Service. Notice 123 – Price List
Two discounts can shave those rates further. Full-Service Intelligent Mail cuts $0.005 per piece, and Seamless Acceptance takes another $0.002 off each automation letter or postcard.3United States Postal Service. Notice 123 – Price List Both require electronic documentation and unique Intelligent Mail barcodes on every piece.
Dropping the Mailing at the BMEU
Commercial mail paid with permit imprint must be brought to a Business Mail Entry Unit. You can’t hand it to a carrier or drop it in a collection box.14Postal Explorer. Business Mail 101 – Where to Go Bring the prepared trays or containers along with the signed Form 3600-FCM.
The clerk checks the mailing for correct sortation, eligibility for the claimed price, proper markings and endorsements, and postage payment, and confirms your advance deposit account has enough to cover it.13USPS. Business Mail 101 – At the Post Office Once the checks clear, the postage is deducted and the mail enters the delivery stream.
Larger mailings may go through MERLIN, the Mail Evaluation Readability Lookup Instrument, which samples pieces to verify barcode quality, print readability, and presort accuracy against DMM standards.15United States Postal Service. MERLIN If sampled pieces fail, you may owe additional postage or need to re-sort part of the mailing.16United States Postal Service. Presort Verification
Filing Electronically Through PostalOne!
You don’t have to submit paper. PostalOne! accepts postage statements electronically through three channels: Postal Wizard, Mail.dat, and Mail.XML.17United States Postal Service. PostalOne! Electronic submission speeds acceptance, cuts data-entry errors, and is required for the Full-Service Intelligent Mail discount.
Registration runs through the Business Customer Gateway.6PostalPro. Business Customer Gateway Postal Wizard is a web tool where you type in the same data the paper form asks for. Mail.dat and Mail.XML are file formats used by mailing software and service providers running large or frequent jobs.
Seamless Acceptance
High-volume mailers who submit electronic documentation can move up to Seamless Acceptance, which replaces manual clerk inspection with automated verification. Eligibility requires Full-Service Intelligent Mail, eInduction, piece-level electronic data, and unique Intelligent Mail barcodes on every piece, tray, and container. New participants run in parallel with traditional acceptance until their error rates stay below USPS thresholds for at least one calendar month, then move into full Seamless.18PostalPro. Seamless Acceptance The payoff is the $0.002 per-piece discount plus faster drop-offs.
What Gets a Mailing Rejected
Most rejections at the BMEU come down to a short list of recurring problems:
- Piece count on the postage statement doesn’t match the physical mail. Recount and file a corrected form, or pay the difference.
- Pieces aren’t presorted to the level claimed. The clerk flags the errors and you re-sort before acceptance.
- Advance deposit account balance is too low. Deposit more before the mailing is released.
- Contents don’t qualify for the price category claimed, such as a flat entered at letter rates or nonmachinable pieces priced as machinable.
- Ancillary service endorsements are missing, misprinted, or placed wrong.
None of these usually kills the mailing outright. You typically get to fix things on-site by recounting, re-sorting, adding funds, or submitting a new postage statement at the corrected price.13USPS. Business Mail 101 – At the Post Office Still, arriving with a clean mailing saves time on both sides. Run your presort software reports, verify piece counts against tray labels, and confirm the account balance before the truck leaves.