# postalref

> An unofficial reference for USPS package barcodes, service type codes and mailing terms.

Unofficial. Not affiliated with or endorsed by the United States Postal Service. Each fact on a page cites the USPS document and the row or page it comes from. An agent can also add https://postalref.com/mcp as an MCP server; its tools only read.

## Pages

- [USPS codes and rules, cited to the page they come from](https://postalref.com/): look up a service type code or a term, decode a tracking number, or ask a question.
- [Products](https://postalref.com/products): 83 pages on USPS products and services, each saying what the product is and citing the USPS documents it quotes.

## Products

- [Address Change Service](https://postalref.com/products/address-change-service): 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.
- [Address Element Correction and AEC II](https://postalref.com/products/address-element-correction): Address Element Correction, or AEC, is a computerized address correction process USPS runs for business mailers.
- [Address Information System products](https://postalref.com/products/address-information-system): Address Information System products, or AIS products, are raw USPS database files that help customers standardize addresses, get address details and correct address records.
- [Address Matching System API](https://postalref.com/products/ams-api): The Address Matching System API, or AMS API, is USPS software that developers use to build address matching software.
- [Alternative Designs](https://postalref.com/products/alternative-designs): Alternative Designs is a set of USPS requirements that lets non-rectangular TED-C letters mail at automation letter prices.
- [Ancillary Service Endorsements](https://postalref.com/products/ancillary-service-endorsement): An ancillary service endorsement is a printed instruction on a mailpiece that tells USPS how to handle it when it is undeliverable as addressed.
- [ANKLink](https://postalref.com/products/anklink): 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.
- [Automated Package Verification (APV) System](https://postalref.com/products/automated-package-verification-apv-system): The Automated Package Verification System, APV, is a USPS system built to capture postage discrepancies.
- [Bulk Parcel Return Service](https://postalref.com/products/bulk-parcel-return-service): 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.
- [Bulk Proof of Delivery Program](https://postalref.com/products/bulk-proof-of-delivery-program): 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.
- [Business Customer Gateway](https://postalref.com/products/business-customer-gateway): The Business Customer Gateway is USPS's single entry point for its online business services.
- [Business Portal](https://postalref.com/products/business-portal-formerly-customer-onboarding-portal): The Business Portal is the USPS website where a business creates and manages its USPS business account and sets up core services.
- [Business Reply Mail](https://postalref.com/products/business-reply-mail): 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.
- [CASS](https://postalref.com/products/coding-accuracy-support-system): CASS, the Coding Accuracy Support System, is USPS's certification of address-matching software.
- [Certificate of Mailing](https://postalref.com/products/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.
- [Computerized Delivery Sequence](https://postalref.com/products/cds): Computerized Delivery Sequence, or CDS, is a USPS program that gives mailers updated delivery sequence information for the address lists they provide.
- [County Project](https://postalref.com/products/county-project): 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.
- [Current Web Service Description Languages (WSDLs)](https://postalref.com/products/current-web-service-description-languages-wsdls): The current WSDLs are the zip files of Web Services Description Language and XML Schema Definition files that USPS posts for Mail.XML.
- [Customer Registration ID (CRID)](https://postalref.com/products/crid): A CRID, or Customer Registration ID, is a USPS-generated number of up to 15 digits that identifies a business at a specific location.
- [DPV](https://postalref.com/products/delivery-point-validated): 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.
- [Drop Shipment Management System](https://postalref.com/products/dsms): 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.
- [DSF2](https://postalref.com/products/dsf2): DSF2 is a USPS address product that tells whether a ZIP + 4 coded address is a known address record in the USPS delivery file.
- [eInduction](https://postalref.com/products/einduction): 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.
- [Election Mail and Political Mail](https://postalref.com/products/election-mail-and-political-mail): Election Mail is any item mailed to or from authorized election officials that enables citizens to take part in voting.
- [Electronic Address Sequencing](https://postalref.com/products/eas): 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.
- [Electronic Documentation (eDoc)](https://postalref.com/products/edoc): Electronic Documentation, or eDoc, is an electronic postage statement that can also carry barcode information and qualification reports for a mailing.
- [Electronic Verification System (eVS®)](https://postalref.com/products/evs): The Electronic Verification System, eVS, is a USPS system that lets parcel shippers document and pay postage by sending electronic manifest files.
- [Enterprise Payment System](https://postalref.com/products/enterprise-payment-system): 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.
- [Enterprise Post Office Boxes Online](https://postalref.com/products/enterprise-post-office-boxes-online): Enterprise Post Office Boxes Online, or ePOBOL, is a USPS online service for opening, closing and paying for PO Boxes, Caller Services and Reserves.
- [Every Door Direct Mail](https://postalref.com/products/every-door-direct-mail): Every Door Direct Mail, or EDDM, is a USPS service that delivers a business's mailpiece to every address in the areas it picks.
- [Facility Access and Shipment Tracking (FAST®)](https://postalref.com/products/fast): 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.
- [Full-Service Assessments](https://postalref.com/products/full-service-assessments): A Full-Service assessment is the postage USPS bills a mailer when its Full-Service errors for a calendar month exceed an error threshold.
- [Full-Service Certification](https://postalref.com/products/full-service-certification): Full-Service Certification is a voluntary USPS certification for mailers that send consistent, high-quality Full-Service mailings.
- [Hazardous, Restricted, and Perishable Mail](https://postalref.com/products/mailability): Hazardous, restricted, and perishable mail is matter that USPS accepts only under the conditions Publication 52 sets.
- [Informed Delivery](https://postalref.com/products/informed-delivery): Informed Delivery is a free and optional USPS notification service that lets eligible residential consumers preview their letter-sized mail and manage incoming packages.
- [Informed Delivery API](https://postalref.com/products/informed-delivery-api-application-programming-interface): The Informed Delivery API is a USPS Application Programming Interface that lets outside integrators communicate with the Informed Delivery application.
- [Informed Visibility Mail Tracking & Reporting](https://postalref.com/products/iv-mtr): 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.
- [Intelligent Mail Barcode](https://postalref.com/products/intelligent-mail-barcode): The Intelligent Mail barcode is a 65-bar USPS barcode used to sort and track letters and flats.
- [Intelligent Mail Container Barcode](https://postalref.com/products/intelligent-mail-container-barcode): 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.
- [Intelligent Mail Matrix Barcode](https://postalref.com/products/intelligent-mail-matrix-barcode): The Intelligent Mail Matrix Barcode, IMmb for short, is a two-dimensional GS1 DataMatrix barcode that USPS uses to route and track packages.
- [Intelligent Mail Package Barcode (IMpb)](https://postalref.com/products/impb): The Intelligent Mail Package Barcode is the USPS-developed barcode on a package label that automated parcel equipment and scanners read.
- [Intelligent Mail Package Barcode (IMpb) ACS](https://postalref.com/products/intelligent-mail-package-barcode-impb-acs): IMpb ACS is a USPS service that gives parcel mailers who print the Intelligent Mail package barcode an electronic address correction.
- [Intelligent Mail Tray Label](https://postalref.com/products/intelligent-mail-tray-label): 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.
- [Labeling Lists](https://postalref.com/products/labeling-lists): 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.
- [LACSLink](https://postalref.com/products/lacslink): 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.
- [Mail Anywhere](https://postalref.com/products/mail-anywhere): Mail Anywhere is a USPS program that lets a mailer use a single permit at any location.
- [Mail Growth Incentives](https://postalref.com/products/mail-growth-incentives): 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.
- [Mail Quality Data through IV-MTR](https://postalref.com/products/mail-quality-data-through-iv-mtr): Mail Quality Data through IV-MTR is a USPS service that gives mailers their uncapped Mail Quality Data through the IV-MTR application.
- [Mailer Identifier (MID)](https://postalref.com/products/mid): The Mailer Identifier, or Mailer ID, is a field in Intelligent Mail barcodes that identifies the mailer.
- [Mailer Scorecard](https://postalref.com/products/mailer-scorecard): The Mailer Scorecard is a USPS online reporting tool that shows mailers the quality of their mail over a calendar month.
- [Mailing Promotions and Incentives](https://postalref.com/products/mailing-promotions): Mailing Promotions are USPS's discount and incentives program for First-Class Mail and USPS Marketing Mail customers.
- [Marriage Mail](https://postalref.com/products/marriage-mail): Marriage Mail is direct mail in which marketing service companies combine advertisements from several companies into one mailpiece, lowering each advertiser's cost.
- [Merchant Returns API](https://postalref.com/products/merchant-returns-api): 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.
- [Move Update](https://postalref.com/products/move-update): 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.
- [Multi-line Accuracy Support System](https://postalref.com/products/multi-line-accuracy-support-system): The Multi-line Accuracy Support System, MASS, is a USPS certification for the machines that read addresses on mail and apply its barcodes.
- [My Products Portal](https://postalref.com/products/my-products-portal): 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.
- [NCOALink](https://postalref.com/products/ncoalink): NCOALink is a USPS dataset of about 160 million permanent change-of-address records from individuals, families and businesses.
- [OneCode ACS](https://postalref.com/products/onecode-acs): OneCode ACS is a USPS service that uses the Intelligent Mail barcode to send mailers electronic address corrections for letters and flats.
- [Package Intercept](https://postalref.com/products/package-intercept): Package Intercept is a paid USPS service that lets a sender or recipient stop or redirect a mailpiece before it goes out for delivery.
- [Parcel Data Exchange (PDX) API](https://postalref.com/products/parcel-data-exchange-pdx-api): 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.
- [Periodicals](https://postalref.com/products/periodicals): Periodicals is the USPS class of mail for newspapers, magazines and other publications sent to an established list of subscribers or requesters.
- [Periodicals Accuracy, Grading, and Evaluation (PAGE) Program](https://postalref.com/products/periodicals-accuracy-grading-and-evaluation-page-program): 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.
- [Phone Provider Format–Hold For Pickup Notifications](https://postalref.com/products/phone-provider-format-hold-for-pickup-notifications): Phone Provider Format–Hold For Pickup Notifications is a USPS chart of the text-message address format for each known cell phone provider.
- [Polywrap and Polywrap Manufacturers](https://postalref.com/products/polywrap-and-polywrap-manufacturers): Polywrap is clear polythene film used to enclose mailpieces, including automation flat-size pieces.
- [Postage Evidencing Systems](https://postalref.com/products/pes): A Postage Evidencing System, or PES, is a postage meter or PC Postage product, which prints indicia on mail to show postage was prepaid.
- [Premium Forwarding Service Commercial](https://postalref.com/products/premium-forwarding-services-commercial): 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.
- [Pricing and Classification Service Center](https://postalref.com/products/pricing-and-classifications-service-center): 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.
- [Product Tracking and Reporting (PTR)](https://postalref.com/products/ptr): Product Tracking and Reporting is the USPS database that stores tracking scan data for all barcoded packages and extra services products.
- [Seamless Acceptance](https://postalref.com/products/seamless-acceptance): Seamless Acceptance is a USPS process that automates the entry and verification of commercial mailings with eDoc, Intelligent Mail barcodes and scan data.
- [Secure Destruction](https://postalref.com/products/secure-destruction): 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.
- [Service Hubs and Facilities](https://postalref.com/products/service-hubs-and-facilities): A service hub is a USPS cross-dock facility where mailers enter properly prepared mail for the delivery units the hub serves.
- [Service Performance Measurement (SPM) Mail Exclusions](https://postalref.com/products/service-performance-measurement-spm-mail-exclusions): 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.
- [Service Type Identifiers (STIDs)](https://postalref.com/products/stids): A Service Type Identifier, or STID, is a three-digit code in the Intelligent Mail barcode that indicates the service type for a mailpiece.
- [Share Mail](https://postalref.com/products/share-mail): 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.
- [Shipper Paid Services](https://postalref.com/products/shipper-paid-services): 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.
- [SuiteLink®](https://postalref.com/products/suitelink): SuiteLink is a USPS data product of business addresses that CASS processing matched only to a building's highrise default.
- [Tech Sheets for APIs, Click-N-Ship, and USPS Ship](https://postalref.com/products/tech-sheets-for-apis-click-n-ship-and-usps-ship): The tech sheets for APIs, Click-N-Ship and USPS Ship are USPS documents about the platforms a business uses to ship packages.
- [Test Environment for Mailers](https://postalref.com/products/test-environment-for-mailers): 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.
- [Traditional ACS](https://postalref.com/products/traditional-acs): Traditional ACS is the original form of Address Change Service, which sends mailers electronic notices of undeliverable mail and changes of address.
- [USPS Picture Permit Indicia](https://postalref.com/products/usps-picture-permit-indicia-ppi): 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.
- [USPS Returns](https://postalref.com/products/usps-returns): USPS Returns is a USPS method for verifying and paying for return packages, built for Merchandise Return Service and Scan Based Payment customers.
- [USPS Ship](https://postalref.com/products/usps-ship): USPS Ship is the USPS platform for paying and verifying postage on commercial packages.
- [USPS Technical Specifications for Mail.dat and Mail.xml](https://postalref.com/products/usps-technical-specifications-for-mail-dat-and-mail-xml): 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.