Products

Address Change Service, or ACS, is a USPS post-mailing service that sends mailers change-of-address information and other reasons for non-delivery electronically. Mailers use the notices to update their mailing lists automatically.

Also on this page: SingleSource ACS™.

Address Element Correction, or AEC, is a computerized address correction process USPS runs for business mailers. It turns problematic addresses into accurate addresses or identifies them as potentially undeliverable. AEC II sends the addresses AEC cannot resolve to delivery offices for review and resolution.

Also on this page: Address Element Correction II (AEC II).

Address Information System products, or AIS products, are raw USPS database files that help customers standardize addresses, get address details and correct address records. Mailers read them with matching software they buy or build, and get a new release each month.

Also on this page: ZIP + 4® Product, City State Product, Five-Digit ZIP® Product, Carrier Route Product, Enhanced Line of Travel (eLOT®), Delivery Statistics Product, Z4CHANGE Product, ZIPMove Product, RDI™, Address Information System (AIS) Viewer.

The Address Matching System API, or AMS API, is USPS software that developers use to build address matching software. It gives that software USPS matching logic, so its users can verify the accuracy of ZIP + 4 returns. Manufacturers build it into their own products under a yearly license from USPS.

Alternative Designs is a set of USPS requirements that lets non-rectangular TED-C letters mail at automation letter prices. A TED-C letter is a letter-size piece with a die-cut that extends past its conventional trailing edge. Mailers check a design with the TED-C Letters Template and need no pre-approval.

An ancillary service endorsement is a printed instruction on a mailpiece that tells USPS how to handle it when it is undeliverable as addressed. Mailers use one to learn an addressee's new address or why a piece was not delivered, and to have it forwarded, returned or disposed of.

ANKLink is an option to the 18-month NCOALink product that tells a mailer a customer moved 19 to 48 months ago, without giving the new address. A mailer uses it to drop the customer from a list or to seek the new address from a Full Service Provider.

The Automated Package Verification System, APV, is a USPS system built to capture postage discrepancies. Its purpose is to recover them automatically, in a way that protects the customer relationship. It sends each postage adjustment to a vendor, who pays or collects it and lets the customer dispute it.

Bulk Parcel Return Service, or BPRS, is a USPS service that returns a high-volume mailer's machinable USPS Marketing Mail parcels to designated postal facilities. It covers parcels USPS can't deliver as addressed and parcels addressees open and remail. The mailer collects the parcels or has USPS deliver them, and pays for each one returned.

The Bulk Proof of Delivery Program is a USPS program that gives mailers signature proof of delivery records for their mailpieces without a request for each one. Mailers use it to keep signature records longer than USPS keeps them and to handle them more efficiently.

The Business Customer Gateway is USPS's single entry point for its online business services. Businesses use it to prepare and track mailings, manage Mailer IDs and permits, and enroll for shipping services.

The Business Portal is the USPS website where a business creates and manages its USPS business account and sets up core services. The account gives the business the identifiers it needs for USPS APIs, USPS Ship and Click-N-Ship. Its former name is the Customer Onboarding Portal.

Business Reply Mail is a First-Class Mail and Priority Mail service in which a sender pays postage and per-piece fees only for the replies it receives. USPS collects that postage and fee only on pieces customers send back. Mailers use it to save postage on large volumes of reply pieces when a response is not assured.

Also on this page: Automated Business Reply Mail® (ABRM) Tool.

CASS, the Coding Accuracy Support System, is USPS's certification of address-matching software. It tests how accurately the software assigns ZIP Codes, delivery point codes and carrier route codes to addresses. Any mailing claimed at an automation price must come from address lists coded with CASS-certified software.

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.

Computerized Delivery Sequence, or CDS, is a USPS program that gives mailers updated delivery sequence information for the address lists they provide. A mailer qualifies by showing that its list holds at least 90 percent of the possible delivery addresses in a ZIP Code. USPS then sends those addresses in walk sequence, the order a carrier delivers them.

The County Project is a free USPS service that checks a local address file against the Address Management System, USPS's database of delivery addresses. USPS returns the matched addresses standardized with their ZIP+4, and lists the addresses, county codes and congressional districts that differ, for both sides to review.

The current WSDLs are the zip files of Web Services Description Language and XML Schema Definition files that USPS posts for Mail.XML. Software developers build Mail.XML software from them. Each download matches one environment, Mail.XML version and message type.

A CRID, or Customer Registration ID, is a USPS-generated number of up to 15 digits that identifies a business at a specific location. A business needs a CRID at its location to submit eDoc, claim Nonprofit rates and receive Full-Service benefits.

Delivery Point Validation, or DPV, is a USPS address management product that tells whether a ZIP + 4 coded address is a known address record in USPS's delivery file. Users run it to confirm known USPS addresses and to find addressing problems that may hinder delivery.

The Drop Shipment Management System, or DSMS, is a USPS program that consolidates plant-verified drop shipment documentation from multiple jobs and locations in electronic files. Authorized mailers and consolidators use it to build consolidated loads of palletized mail, described on electronically created PS Forms 8125-CD.

DSF2 is a USPS address product that tells whether a ZIP + 4 coded address is a known address record in the USPS delivery file. It also gives an address's attributes, such as vacant, residential, business or seasonal. DSF2 processing is one approved way to put mail in walk sequence without a simplified address.

eInduction is a USPS process that checks the payment and preparation of commercial mail containers by scanning their barcodes against the mailer's electronic documentation. It handles drop shipments and expedited plant load mailings without paper PS Forms 8125 and 8017.

Also on this page: eInduction Certification.

Election Mail is any item mailed to or from authorized election officials that enables citizens to take part in voting. Political Mail is material mailed for campaign purposes by candidates, campaign committees, parties and advocacy groups. Live ballots and Political Mail each carry their own Service Type Identifiers and a colored tag, so USPS can see them in its network.

Electronic Address Sequencing, or EAS, is USPS's electronic service for sequencing a mailer's address file and qualifying it for Computerized Delivery Sequence, or CDS. A list qualifies for CDS updates when it holds at least 90 percent of the possible deliveries in a ZIP Code or address group.

Electronic Documentation, or eDoc, is an electronic postage statement that can also carry barcode information and qualification reports for a mailing. Mailers submit it to PostalOne! in place of hardcopy postage statements and qualification reports. It is required for Full-Service Intelligent Mail and Seamless Acceptance.

The Electronic Verification System, eVS, is a USPS system that lets parcel shippers document and pay postage by sending electronic manifest files. Shippers use it for permit imprint parcels across several mail classes. USPS has replaced eVS with USPS Ship.

The Enterprise Payment System, or EPS, is the USPS system that lets business customers pay for postal products and services through one account, the Enterprise Payment Account. Customers fund that account by ACH Debit from their bank or by prefunding a Trust Account.

Enterprise Post Office Boxes Online, or ePOBOL, is a USPS online service for opening, closing and paying for PO Boxes, Caller Services and Reserves. A business links its boxes to an Enterprise Payment Account, and ePOBOL renews their fees automatically.

Every Door Direct Mail, or EDDM, is a USPS service that delivers a business's mailpiece to every address in the areas it picks. The pieces need no names or street addresses. Businesses use it to send postcards, menus, flyers and coupons to the neighborhoods near them.

Facility Access and Shipment Tracking, or FAST, is the USPS system mailers use to give postal facilities advance notice of drop shipment and origin-entered mailings. Business mail owners, preparers and schedulers use it to make appointments and see their scheduled mailings at each facility.

A Full-Service assessment is the postage USPS bills a mailer when its Full-Service errors for a calendar month exceed an error threshold. It removes the Full-Service discount from the pieces in error above the threshold. The eDoc submitter pays it or requests a review.

Full-Service Certification is a voluntary USPS certification for mailers that send consistent, high-quality Full-Service mailings. It has two levels, Standard and Platinum, and USPS lists certified mailers on PostalPro. A separate USPS list names the vendors whose Full-Service software is certified.

Also on this page: Standard Full-Service Certification for Mailers, Platinum Full-Service Certification, Certified Full-Service Software Vendors.

Hazardous, restricted, and perishable mail is matter that USPS accepts only under the conditions Publication 52 sets. Some of it may harm people or property, other agencies' rules limit some, and some can spoil. Mailers use those conditions to learn what they may mail and how to package it.

Also on this page: Toy Propellant Devices, Safety Fuse, Lighters, Ethanol Based Flammable Liquids & Solids, Category B Infectious Substances, Sharps and Regulated Medical Waste, Drug Mailback Program, Cigarettes, Smokeless Tobacco, and Electronic Nicotine Delivery Systems (ENDS), USPS® Container Requirements for Adult Birds.

Informed Delivery is a free and optional USPS notification service that lets eligible residential consumers preview their letter-sized mail and manage incoming packages. Mailers use it to pair a mailpiece with digital content and to gather impressions, interactions and insights from it.

Also on this page: USPS Informed Delivery PostalOne! eDoc Technical Support for Mailers.

The Informed Delivery API is a USPS Application Programming Interface that lets outside integrators communicate with the Informed Delivery application. Mailers and shippers use it to manage interactive Informed Delivery campaigns from their own front-end applications.

Informed Visibility Mail Tracking & Reporting, IV-MTR, is the USPS application that gives commercial mailers near real-time tracking data for domestic-bound mail and its containers. Mailers use the data to manage operations, refine processes and adjust marketing campaigns.

The Intelligent Mail barcode is a 65-bar USPS barcode used to sort and track letters and flats. One barcode can carry requests for many services at once. Mailers must print it on letters and flats prepared for automation prices.

Also on this page: Intelligent Mail® Barcode (IMb) Encoder Software and Fonts, Intelligent Mail® for Small Business Mailers (IMsb).

The Intelligent Mail Container barcode, or IMcb, is a barcode on mailer-generated pallet labels that identifies each pallet or similar container and its mail owner. It ties each container to one mailing, so USPS can track it as it is loaded and unloaded. It holds 21 characters, printed as a GS1-128 or a GS1 DataMatrix barcode.

The Intelligent Mail Matrix Barcode, IMmb for short, is a two-dimensional GS1 DataMatrix barcode that USPS uses to route and track packages. It holds the same data as the package's Intelligent Mail Package Barcode, the linear IMpb. The IMmb lets USPS still read a package when its IMpb becomes unreadable.

The Intelligent Mail Package Barcode is the USPS-developed barcode on a package label that automated parcel equipment and scanners read. It holds the routing and tracking data USPS uses to sort and track each package. Shippers who meet its requirements get the best commercial prices and piece-level tracking at no extra charge for most products.

Also on this page: USPS Tracking Electronic Services Certification.

IMpb ACS is a USPS service that gives parcel mailers who print the Intelligent Mail package barcode an electronic address correction. A shipper registers its Mailer ID, and a printed ancillary service endorsement on the parcel then triggers an electronic notice.

The Intelligent Mail Tray Label is the label on a tray, tub or sack of mail whose 24-digit barcode identifies that one unit and the mailer who prepared it. USPS uses it to identify every tray, tub and sack as it moves through mail processing and delivery. Mailers print it to USPS specifications or create it online.

Also on this page: Customer Label Distribution System (CLDS), Intelligent Mail® Tray Label Certification.

Labeling Lists are a USPS data product of 3- and 5-digit ZIP Codes and the destinations that containers of mail for them are labeled to. Mailers who presort mail use them to combine pieces into containers and label each one. The lists change often, and USPS publishes each change in the Postal Bulletin.

LACSLink is a secure USPS dataset of converted addresses, mostly from the 911 emergency system, which often changed rural-style addresses to city-style ones. Address-matching software looks up an old address in it and returns the new one, so a mailer can update its mailing list.

Mail Anywhere is a USPS program that lets a mailer use a single permit at any location. The permit that pays the postage is not local to the facility that verifies the mail. Taking part requires submitting mailings electronically.

Mail Growth Incentives are USPS offers of postage credit to registered Mail Owners whose qualifying First-Class Mail or Marketing Mail volume grows past a threshold. The postage credit is 30% of the added pieces times the average price paid per piece. Mail Owners can use it only on qualifying mail in the class that earned it.

Mail Quality Data through IV-MTR is a USPS service that gives mailers their uncapped Mail Quality Data through the IV-MTR application. The data is the error detail behind the Mailer Scorecard. Mailers get it as daily, weekly or monthly data feeds.

The Mailer Identifier, or Mailer ID, is a field in Intelligent Mail barcodes that identifies the mailer. USPS assigns it as a 6-digit or 9-digit number, based on annual mail volume. Mailers print it in their barcodes and use it in eDoc to name the mail preparer and the mail owner.

The Mailer Scorecard is a USPS online reporting tool that shows mailers the quality of their mail over a calendar month. USPS uses its results to decide when a mailer owes additional postage. Mailers use it to find quality problems and fix them.

Also on this page: Full-Service Report Testing: Service Type Identifier (STID) Errors.

Mailing Promotions are USPS's discount and incentives program for First-Class Mail and USPS Marketing Mail customers. Each promotion takes a percentage off postage, on the postage statement, for mail that meets its requirements. Mailers send USPS their mailpiece samples and their questions about the promotions through a portal.

Also on this page: Guide to Promotions & Incentives Program, 2026 Promotions Calendar and Technical Information, 2025 - 2026 - Catalog Insights Promotion, Informed Visibility Data Feed Instructions.

Marriage Mail is direct mail in which marketing service companies combine advertisements from several companies into one mailpiece, lowering each advertiser's cost. USPS gives qualifying marriage mailpieces a discounted price, the Marriage Mail Incentive. Its Plus One product adds an advertising card to a marriage mailpiece.

Also on this page: Marriage Mail Price Incentive, Plus One Product.

The Merchant Returns API is a USPS web service that makes return shipping labels for customers of merchants enrolled in the USPS Merchant Return Program. A merchant's application requests one label or a bulk set, as a PDF, TIF or PNG image. Merchants offer the labels from their own websites and pay for them.

Move Update is the USPS standard that cuts the mail needing forwarding or return by matching a mailer's address records with USPS change-of-address orders. To get commercial First-Class Mail or USPS Marketing Mail prices, a mailer must show its addresses were updated within 95 days before the mailing date.

Also on this page: 99% Testing.

The Multi-line Accuracy Support System, MASS, is a USPS certification for the machines that read addresses on mail and apply its barcodes. It is an extension of CASS, the certification that improves the accuracy of postal codes on mail. A mailer needs it to barcode mail with these machines at automation rates.

The My Products Portal is USPS's online portal for First-Class Mail and Marketing Mail customers who take part in its discounts and incentives. Mailers use it to submit mailpiece samples and ask questions about the promotions. Mail Owners also register for Mail Growth Incentives in it.

Also on this page: Guide to the My Products Portal, How to Enroll in the Promotions, Integrated Technology Enrollment Guide, 2025 Informed Delivery MPP Integration, eDoc Submitter Permit Enrollment Guide, My Products Portal Multiple Pre-Approval Requests (Batch Upload), Guide to the My Products Portal, Guide to the My Products Portal (Formerly Mailing Promotions Portal).

NCOALink is a USPS dataset of about 160 million permanent change-of-address records from individuals, families and businesses. Mailers use it to update the addresses on a mailing list before they mail. USPS provides the data only to companies it licenses.

Also on this page: Mail Processing Equipment Service Provider Licensees.

OneCode ACS is a USPS service that uses the Intelligent Mail barcode to send mailers electronic address corrections for letters and flats. The mailer matches each notice to its list by the barcode's serial number and corrects the address.

Package Intercept is a paid USPS service that lets a sender or recipient stop or redirect a mailpiece before it goes out for delivery. The intercepted mailpiece goes back to the sender, to a new domestic address, or to a Post Office to be held for pickup. Businesses request intercepts in the Business Customer Gateway.

Parcel Data Exchange, or PDX, is a USPS web and API application that lets customers send manifest files to USPS and receive outbound files from it. Parcel shippers use it to send Shipping Services Files and get extracts and error-warning reports through a secure web service, not FTP or SFTP.

Periodicals is the USPS class of mail for newspapers, magazines and other publications sent to an established list of subscribers or requesters. A publisher with Periodicals mailing privileges pays for each mailing at prices set partly by how much of the issue is advertising.

PAGE is a voluntary USPS program that tests whether publication and print planning software calculates the percentage of advertising according to Domestic Mail Manual standards. Periodicals mailers who use PAGE-certified software can stop submitting marked copies of every edition, unless postal officials ask for them. USPS certifies both the software and the people who operate it.

Phone Provider Format–Hold For Pickup Notifications is a USPS chart of the text-message address format for each known cell phone provider. A mailer gives USPS an SMS text address so the recipient gets a text about a Hold For Pickup package. The Shipping Services File's format for that number no longer includes the provider's carrier URL.

Polywrap is clear polythene film used to enclose mailpieces, including automation flat-size pieces. USPS approves a polywrap film for automated flat processing once it passes an approved laboratory's tests under USPS-T-3204, the specification for testing the film. Mailers who polywrap automation-rate flats must use approved polywrap.

A Postage Evidencing System, or PES, is a postage meter or PC Postage product, which prints indicia on mail to show postage was prepaid. USPS regulates PES and their use under 39 CFR Part 501 to protect postal revenue.

Premium Forwarding Service Commercial is a USPS service that temporarily forwards a business's mail to another domestic address by Priority Mail Express or Priority Mail. The business sets the shipment days and how long forwarding lasts. It pays an annual enrollment fee, plus postage for each shipment.

The Pricing and Classification Service Center, or PCSC, is a USPS national center that makes classification decisions on price application, mail eligibility and mailing standards. It serves both mailers and USPS field employees. It also gives guidance on mailing standards and decides customer requests for exceptions.

Product Tracking and Reporting is the USPS database that stores tracking scan data for all barcoded packages and extra services products. It sends tracking updates to USPS.com, Informed Delivery and external APIs. Mailers send it data on each package and get back a scan event extract file and a Confirmation/Error/Warning file.

Seamless Acceptance is a USPS process that automates the entry and verification of commercial mailings with eDoc, Intelligent Mail barcodes and scan data. It is for Full-Service mailers who take part in eInduction. Their postage statements finalize on their own, which puts postage payment in the mailer's hands.

Also on this page: Seamless Acceptance Incentive.

Secure Destruction is an opt-in USPS service that shreds and recycles undeliverable First-Class Mail letters and flats that would otherwise go back to the sender. A mailer asks for it with a Secure Destruction STID, a code in each piece's Intelligent Mail barcode. USPS then sends a daily electronic notice of the pieces it sorted for destruction.

A service hub is a USPS cross-dock facility where mailers enter properly prepared mail for the delivery units the hub serves. Mail prepared to the hub guidelines gets the DSCF rate. USPS publishes a list of the hubs and the 5-digit offices each one serves.

Service Performance Measurement (SPM) Mail Exclusions is a set of USPS information and tools for Full-Service commercial mailers on mail left out of service measurement. It helps those mailers get more of their mail into USPS service measurement. Its SPM Exclusion by CRID tool, in the Business Customer Gateway, reports a mailer's excluded mail.

A Service Type Identifier, or STID, is a three-digit code in the Intelligent Mail barcode that indicates the service type for a mailpiece. It marks the piece as Full-Service or basic, and it sets how USPS handles undeliverable mail and which address correction the mailer gets.

Share Mail is a way for a business to hand out First-Class Mail letters and postcards that people can mail on to others without a stamp. The business that produces the pieces, the account holder, pays their postage. Businesses and organizations use it for referral marketing.

Shipper Paid Services is an Address Change Service option that gives parcel mailers electronic address corrections and bills forwarding or return postage to their account. Paying the forwarding postage this way makes it less likely that the addressee refuses the parcel.

SuiteLink is a USPS data product of business addresses that CASS processing matched only to a building's highrise default. Address matching software uses it to add the known suite number, so USPS can sequence the mail for delivery. USPS offers SuiteLink at no charge.

The tech sheets for APIs, Click-N-Ship and USPS Ship are USPS documents about the platforms a business uses to ship packages. The USPS APIs let a business's software price packages, create labels and track them. USPS Ship charges each package's postage to the shipper's account and checks it against scan data.

The Test Environment for Mailers, TEM, is a USPS test platform where mailers test their ability to submit electronic mailing information, such as Full-Service mailings. Mailers get their software approved in TEM before they move to production. Mailer Customer Acceptance Testing is a separate test environment for USPS Ship and USPS API users.

Also on this page: Testing Environment for Mailers (TEM) Using Mail.XML, Mailer Customer Acceptance Testing (MCAT).

Traditional ACS is the original form of Address Change Service, which sends mailers electronic notices of undeliverable mail and changes of address. A mailer prints a USPS-assigned Participant ID and an optional keyline in the address block and needs no Intelligent Mail barcode. The notices arrive, for a fee, on USPS's Electronic Product Fulfillment website.

USPS Picture Permit Indicia is a USPS option that puts an organization's color logo, brand image or trademark in the permit imprint on its mail. It is for automation First-Class Mail letters and postcards and automation USPS Marketing Mail letters, for a fee per piece on top of postage. Mailers use it to make their brand easier to recognize.

USPS Returns is a USPS method for verifying and paying for return packages, built for Merchandise Return Service and Scan Based Payment customers. A business gives its customers prepaid return labels. USPS prices each returned package on its own and charges the business's Enterprise Payment System account.

USPS Ship is the USPS platform for paying and verifying postage on commercial packages. Shippers send a manifest, USPS Ship compares it with scans of the physical packages, and USPS charges or refunds the difference.

USPS Technical Specifications for Mail.dat and Mail.xml are the USPS documents that say how PostalOne! accepts mailing data in the two industry formats. Technical programmers and managers use them to build software that submits electronic documentation for mailings.