Welcome to the Web Tools API Portal

USPS has the solution to your e-commerce API and shipping API needs. The Web Tools® API library enables external e-commerce shopping cart and shipping software to access valuable USPS® data—free of charge! From shipping rates to tracking information to scheduling a package pickup, Web Tools makes shipping with the U.S. Postal Service® easier than ever. Get started now or read on to learn more.

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Web Tools 2019 Release Notes (PDF)

Updated documentation is now available (Updated 12/28/2018).

New label API restrictions will take effect February 23, 2018.
• Label API Restrictions Notice - PDF
• Label API Restrictions FAQs - PDF
• Customer Options – Postage Labels - PDF


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Receive email notifications about Web Tools maintenance updates.

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Easy as 1, 2, 3!

  1. Developer Center

    Developer Center

    Start making live calls to Web Tools APIs and integrate with USPS Web Tools® to make shipping easier for you and your clients.

    Register NowView FAQs

    Once registered, you’ll receive an email with your assigned Web Tools User ID. You’ll then have access to our most popular offerings like the shipping rate, tracking information, and ZIP™ code APIs. For access to more secure APIs, like Label Printing and Package Pickup, you’ll need additional permissions. Contact our Internet Customer Care Center (uspstechnicalsupport@mailps.custhelp.com) with the following information:

    • “Web Tools API Access” in the subject line of the email
    • Which Label APIs you want to access
    • If you’ll be modifying the label image

    Image of three guys in conversation in front of a laptop and half-eaten pizza.

    View API Technical Documentation

    Save time and money by reducing shipping errors due to incorrect address entry. This tool corrects errors in street addresses, including abbreviations and missing information. It also supplies a ZIP+4® Code.

    View Technical Document

    Test XML Request

    Address Validation

    http://production.shippingapis.com/ShippingAPI.dll?API=Verify&XML=<AddressValidateRequest USERID="xxxxxxxxxxxx">

    <Address2>6406 Ivy Lane</Address2>


    Zip Code Lookup


    <Address2>6406 Ivy Lane</Address2>


    City/State Lookup

    http://production.shippingapis.com/ShippingAPI.dll?API=CityStateLookup&XML=<CityStateLookupRequest%20USERID=" xxxxxxxxxxxx">

    <ZipCode ID= "0">


    Get estimated delivery information and track any package shipped via Priority Mail Express®, Global Express Guaranteed®, or Priority Mail Express International™ services. Check the tracking information for packages shipped with USPS Tracking®, Signature Confirmatiom™, Certified Mail®, or Registered Mail™ services.

    View Technical Document

    Test XML Request

    http://production.shippingapis.com/ShippingApi.dll?API=TrackV2&XML=<TrackFieldRequest USERID="xxxxxxxxxx">



    Integrate with our Shipping Label APIs to print shipping labels with a tracking barcode.

    Electronic Merchandise Return Service Labels API

    Let online customers print return labels for Priority Mail, First-Class Mail, Standard Post, Media Mail, and Library Mail services.

    View Technical Document

    Get estimated and guaranteed delivery dates with Service Standards and Commitments APIs.

    Test XML Request

    Priority Mail Service Standards

    http://production.shippingapis.com/ShippingAPI.dll?API=PriorityMail&XML=<PriorityMailRequest USERID="xxxxxxxxxxxx">


    View Technical Document

    First Class Mail Service Standards

    http://production.shippingapis.com/ShippingAPI.dll?API=FirstClassMail&XML=<FirstClassMailRequest USERID=" xxxxxxxxxxxx ">


    View Technical Document

    Priority Mail Express® Service Commitments

    http://production.shippingapis.com/ShippingAPI.dll?API=ExpressmailCommitment&XML=<ExpressMailCommitmentRequest USERID=" xxxxxxxxxxxx ">


    View Technical Document

    Service Delivery Calculator

    http://production.shippingapis.com/ShippingAPI.dll?API=StandardB&XML=<StandardBRequest USERID="xxxxxxxxxxxx">


    View Technical Document

  2. Shipper Support Center

    Shipper Support Center

    USPS Web Tools® are e-commerce application program interfaces (APIs) that can be used for online stores or customer service centers – free of charge.

    Have an E-commerce Website?

    Get access to our Web Tools through a simple registration process.

    Register NowView FAQs about Online Shipping

    Once registered, you’ll receive an email with your assigned Web Tools User ID. You’ll then have access to the most popular APIs. For access to more secure APIs, like Label Printing and Package Pickup, you’ll need additional permissions. Contact our Internet Customer Care Center (uspstechnicalsupport@mailps.custhelp.com) with the following information:

    • Price Calculators
    • Package Tracking
    • Service Standards & Commitments
    • Address Information

    Want to hire a professional?

    To assist companies that need help integrating USPS Web Tools® into their sites, the Postal Service™ publishes contact information for some companies willing to provide services that meet our criteria. These lists are not exhaustive and being listed is not an endorsement by USPS®.

    Image of female business owner standing in her shop.

    USPS Web Tools® Integrators

    Some companies that may be able to assist with the integration of USPS Web Tools® or help you build a customer solution using Web Tools e-commerce APIs.

    View List of Integrators (RTF)

    USPS Web Tools® Product Providers

    Some companies that sell products with Web Tools already integrated.

    View List of Product Providers (RTF)

    Contact Us

    If you have technical questions or need more information, contact the Internet Customer Care Center (ICCC).


    Contact Information

    Email: uspstechnicalsupport@mailps.custhelp.com

    Phone: 1-800-344-7779


    Hours of Operation

    Monday-Friday: 8:00am-8:30pm EST
    Saturday: 8:00am-6:00pm EST
    Closed: Sunday and Postal Holidays
    Open Holidays: 9:00am-6:00pm EST

    • Martin Luther King Day
    • President's Day
    • Columbus Day
    • Veteran's Day

    Shipper Support Center FAQs

    Why are my Web Tools credentials not working when I try to login on USPS.com? Expand Collapse FAQ question

    For shippers using a third party shipping software or shopping cart provider, we recommend you refer to your software provider for instructions to begin offering USPS® services and, take note of relevant information provided in the registration email and links below. For developers integrating Web Tools into a custom application, we specifically recommend:

    The production URLs included in the email confirming your registration with Web Tools are not links to a viewable website. These URLs must be included in the XML Request used to connect to our APIs (please refer to our technical documentation) for more information. If you are using a third party ecommerce software, it’s possible that these URLs are not required, and therefore, do not apply to all customers using our APIs. Please contact your software provider for more specific details concerning integration requirements.

    Since USPS does not know every specific integration requirements of all the possible software options available, we recommend that customers first contact their provider to troubleshoot integration-specific questions.

    We will be happy to assist all customers provided the following information is included when contacting our Internet Customer Care Center at uspstechnicalsupport@mailps.custhelp.com.

    Customers must provide:

    • Copy of a sample XML request resulting in the issue or error, pasted into the body of the email
    • Complete description of exact issue you are experiencing
    • Name of API
    • Name of third party software provider

    Please note that without the above information, our USPS agents will not have sufficient information to investigate Web Tools API issues properly.

General Web Tools FAQs

Are the USPS APIs free? Expand Collapse FAQ question

Get access to USPS APIs when you register for a Web Tools user account.

Register Now

Once registered, you will automatically receive an email containing your assigned Web Tools User ID. After you receive this email, you can use the following APIs:

  • Price Calculators
  • Package Tracking
  • Service Standards & Commitments
  • Address Information
  • Package Pickup

The API containing "Certify" is our testing API and will print labels with the sample watermark. In order to generate actual labels, you must remove "Certify" from all of your Web Tools XML requests.

We currently only offer Every Door Direct Mail® (EDDM) services through our online application at.

Learn More

In order to provide the very best API offering, we periodically update our systems which may require current customers to update their software. To determine if these changes/updates apply to you, refer to our most recent Release Notes. This document contains all new changes and steps to resolve if you are affected. Please remember to first contact your software provider for any integration-related questions.