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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. 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.

Updated October 28, 202628 sources

What it is

The USPS APIs are interfaces that a business's own software calls to ship with USPS. With them, an integrator standardizes an address, prices a package, creates a label, schedules a pickup and tracks the package. Developers start at the USPS Developer Portal, https://developer.usps.com, which has coding examples and downloadable specifications.

Click-N-Ship is an online platform where customers prepare and manage shipments.

USPS Ship is a USPS platform for commercial package payment, verification and end-to-end visibility. It prices each package from the manifest the shipper sends, then checks that price against what USPS scans.

Product Tracking and Reporting, USPS's tracking platform, receives the scan events of barcoded packages. It delivers them three ways: the Tracking API, the Tracking Webhook and Scan Event Extracts.

How it works

A business that pays through USPS Ship makes its labels with its own software, with Click-N-Ship, or through the USPS APIs.

How USPS Ship charges and checks the postage on a package.

  1. The shipper sends USPS a manifest file with each package's weight, dimensions, packaging, entry and postage.
  2. USPS Ship validates and prices each package from the manifest's rate ingredients.
  3. USPS Ship charges the shipper's Enterprise Payment Account on the day it processes the manifest.
  4. USPS compares the manifest with the package attributes its scan data captures.
  5. USPS Ship charges any underpayment, or refunds any overpayment, to the Enterprise Payment Account.
  6. The shipper sees charges and adjustments in online reports and Informed Visibility Mail Tracking & Reporting data feeds.

When a package fails to price, USPS Ship updates its rate ingredients so that as many packages as possible are priced.

The USPS APIs

A label starts with a call to the payment account endpoint, which sets up payment and each party's role. The endpoint supports single and multi-party billing. A label needs a payer and a label owner, and the other roles are optional. The label owner is the Mailer ID used to create the tracking number and the manifest files.

Commercial rates apply by default. Contract rates need an authorized USPS payment account or permit in the payment account call. The label call then calculates postage, standardizes the addresses and generates the Shipping Services File.

USPS offers these APIs:

  • Domestic Labels creates domestic labels and the Shipping Services File that goes with them.
  • International Labels creates international outbound labels and customs forms. Its sequence numbers come from a USPS sales representative.
  • SCAN Form links many labels to one Electronic File Number and a printed PS Form 5630.
  • Domestic Prices and International Prices return commercial or contract rates for a package.
  • Locations finds the closest Post Office or destination entry facility for a destination ZIP Code.
  • Service Standards finds delivery standards or estimated delivery dates between two ZIP Codes.
  • Carrier Pickup schedules a pickup at no extra cost, Monday through Saturday except holidays.
  • The Tracking API shows a package's tracking details as it moves through the USPS network.
  • Organizations registers customers with USPS by creating customer and mailer IDs.
  • Addresses verifies and standardizes a domestic address and adds a missing ZIP Code or ZIP Code + 4.

USPS scans the SCAN Form at acceptance, which gives each linked label an acceptance tracking event.

Tracking data

The Tracking API returns a package's latest detailed tracking information when asked, by tracking number. The Tracking Webhook pushes scan events as they happen, for one tracking number or a whole Mailer ID. A Scan Event Extract is a file of every scan event on packages whose barcode holds the subscriber's Mailer ID.

PTR2 is the platform that replaces PTR, and it runs alongside PTR until customers finish moving to it. Its scan events reach the API and extracts up to 30 minutes sooner. USPS planned to move usps.com, Informed Delivery, and email and text notifications to PTR2 on January 10, 2026. The WebTools platform carried the Tracking API until its retirement on January 25, 2026.

PTR2 retires several events in every channel, among them two alerts about Mailer ID use.

Events PTR2 retires in every channel. It also retires NT, In Transit to Next Facility.

PTR Domestic Scan Events, October 2026
EventExtract descriptionStatus categoryWhat it means
EFDEPART USPS FACILITYIn TransitSortation process at the distribution facility is complete; the item is being dispatched on the next available transportation to the next processing facility or the destination delivery unit
LXPROCESSING EXCEPTIONAlertUSPS has detected a processing irregularity for the item.
MUALERT MID USER NEEDS TO BE REGISTEREDn/aThis is generated when the PIC MID does not exist in PTR's customer reference data.
MXALERT MID HAS BEEN INACTIVATEDn/aThis is generated when the mailer ID in the EFN is not certified. This also gets generated if the PIC MID is not certified.

4 codes in the PTR Domestic Scan Events, October 2026, where Event is EF or LX or MU or MX.

PTR2 stops posting these two alerts to the mail pieces themselves. Mailers still receive the warnings, outside the package's tracking.

Access to tracking data

Starting April 2026, USPS controls access to all three channels to improve security and combat fraud. The Tracking API and Tracking Webhook stay free for end merchants, shippers, platforms and label providers. Other businesses pay a monthly fee. Paid use is charged by tracking number, so one call with 35 tracking numbers counts as 35 requests.

A Scan Event Extract is free only when it goes to a server owned by the customer who registered the Mailer ID. Software vendors whose customers submit manifests with their own credentials don't get free tracking data.

Access to another business's packages rests on two authorizations for selected Mailer IDs. MID authorization gives label providers and consolidators label generation, rates and tracking. Tracking authorization gives service providers and other companies tracking data only.

Customer Data Extract users who want tracking data on shipments they have no part in must sign an Intellectual Property agreement with USPS, for a nominal fee. Paid users put a payment token, holding the Enterprise Payment Account from that agreement, in each request or subscription.

How a service provider sets up access to its shippers' tracking data.

  1. The provider contacts USPS through Email Us to start the order form and Intellectual Property agreement.
  2. The provider sets up an Enterprise Payment Account for payment.
  3. USPS finalizes the order form with the provider's pricing and a confidentiality clause.
  4. The provider signs the Intellectual Property agreement and acknowledges the Terms & Conditions.
  5. USPS configures the provider's Business Portal account so shippers can select it as their service provider.
  6. The merchants delegate tracking authorization to the provider in the Business Portal.

Moving from eVS

USPS is retiring eVS, the electronic verification system, and eVS customers had to move to USPS Ship or the USPS APIs by February 2025. The move includes Click-N-Ship Business Pro, a downloadable label program in the Business Customer Gateway.

All eVS shippers were enrolled in USPS Ship Pilot. The pilot shows how USPS Ship processes a shipper's manifests and scans while eVS still collects the postage. At go-live, USPS switches the shipper's USPS Ship profile to Live on the first day of a month. The eVS profile switches to Parallel, and adjustments are charged in USPS Ship, not eVS.

Rules

You may only use mailer ID (MID) based Services for the MIDs for which You have been authorized by the MID owner and only for as long as the MID owner has given you permission.

A USPS API user may use Mailer ID services only for Mailer IDs whose owner authorized it, and only while that permission lasts.

Intelligent Mail Package Barcodes (IMpb) on individual packages must remain unique for a 120-day period.

A package's Intelligent Mail Package Barcode must not repeat on any other package for 120 days.

Manifests are required for all outbound packages.

Every outbound package must appear in a manifest.

Before April 1, 2026, customers who use label providers, consolidators, and/or enterprise software vendors must confirm proper authorization through the Business Portal for their MIDs.

A customer who uses a label provider, consolidator or software vendor must confirm, in the Business Portal, that provider's authorization for its Mailer IDs.

Takes effect April 1, 2026

You are required to report any suspected fraudulent activity or security vulnerabilities encountered while using the APIs, credentials or Services.

A USPS API user must report any suspected fraud or security weakness it meets while using the APIs or its credentials.

You are responsible for the security of the data once received from the Services or APIs and any breach of the security of the data or transmissions must be reported within 72 hours to cybersafe@usps.gov.

A user must report any breach of the data it receives, or of its transmissions, to cybersafe@usps.gov within 72 hours. The user is responsible for keeping that data secure.

If You have knowledge of Your credentials or data from the Services being transferred to systems and platforms outside of Your control, you must notify the USPS immediately.

A user who learns that its credentials or USPS data have moved to systems it doesn't control must tell USPS at once.

To enroll in USPS Ship, customers must have a USPS business account with a Customer Registration ID (CRID), Mailer ID (MID) and an Enterprise Payment Account (EPA).

A shipper must have a USPS business account to enroll in USPS Ship. The account must hold a Customer Registration ID, a Mailer ID and an Enterprise Payment Account.

What goes wrong

  • A census adjustment covers a difference between the manifest and what USPS measures in processing. It is charged when the package is delivered, or 7 days after its last physical scan.
  • Packages entered at a Destination Delivery Unit are sampled. A shortfall in the sample is extrapolated across the shipper's packages for that mail class and month. USPS Ship charges it when the packages exceed the 1.5% Statistical Quality Assessment threshold.
  • USPS Ship finds duplicate packages by pattern recognition on tracking scans. A duplicate without measurements is priced at a monthly average, and its postage is assessed on the 16th of the following month. The shipper pays for every duplicate.
  • A package scanned with no manifest gets an Unmanifested warning. The shipper has until the 7th of the following month to send one, and USPS Ship collects the postage on the 16th.
  • An unmanifested fee applies when more than 4% of a shipper's packages in a month are unmanifested. It is collected on the 16th of the following month.
  • Package Quality Noncompliance fees apply when a manifest's noncompliant packages exceed the allowed thresholds. The barcode check confirms each barcode is unique and its Mailer ID registered. These fees are collected on the 16th of the following month.
  • Duplicate packages, and sampled packages with no manifest, are subject to interception.

USPS may revoke API credentials, or deny access, for a breach of the terms or for activity that is fraudulent or suspected to be. It may limit a user's API use when it believes the user is data mining or building address lists. A user agrees not to use the APIs or their data to make false or copied labels, tracking IDs, Mailer IDs or counterfeit postage labels.

At registration, USPS may analyze the user's device, called Device Reputation, to confirm the user is who they claim to be. A user who doesn't allow that analysis may be refused access. USPS may use information about a user's API use for investigation, law enforcement and the prosecution of fraud.

Terms

USPS Application Programming InterfacesUSPS APIs, USPS API Platform, USPS suite of APIs
include online interfaces and access that allows You to download data from the USPS related to your mailing, package or shipping activities
Click-N-ShipCNS, Click-N-Ship (CNS)v2 / Enhanced Click-N-Ship
allows submission of an electronic SSF with manifest, tracking, and postage payment. Available for smaller mailers who do not use a software vendor and do not presort their mail.
USPS ShipPPC, Package Platform Concept, Package Platform
The USPS payment and verification platform for outbound packages is called USPS Ship. This platform provides reporting, pricing and visibility as packages move through the mail stream.
Label Owner
The mailer ID used to create the tracking number and generate manifest files
Payer
Who is paying the postage
USPS Tracking APITracking APIs, PTR Tracking API
User requests one-time update of the latest detailed tracking information, including package status and delivery updates, for a specific tracking number.
Tracking WebhookWebhook, Webhook Subscriptions
User subscribes to be pushed to scan events as they occur in near-real-time, for a specific tracking number or Mailer ID.
scan event extract fileCDE, Scan Event Extracts (PTR), Scan Event Extract, Customer Data Extract, Customer Daily Extract
This file contains every scan event that occurs on every package that the mailer included in the Shipping Services file.
MID authorization
provides label providers and consolidators with access to label generation, rates and tracking for select MIDs
Tracking authorization
provides service providers and other companies with access to tracking data for select MIDs
census adjustments
Any differences found may result in a postage adjustment
Device Reputation
an analysis of Your device

Documents

Tech Guides

User Guides

Release Notes

Contacts

  • The USPS Ship Helpdesk takes questions at uspsshipsupport@usps.gov or 1-877-672-0007 Option 7, Option 1.
  • USPS API Support is at APISUPPORT@usps.gov.
  • The Customer Access Technology team handles MID authorization for service providers at https://emailus.usps.com/s/web-tools-inquiry.
  • A breach of USPS API data is reported to cybersafe@usps.gov.

Sources