• I get an 'invalid client credentials' failure when I try to request an OAuth token.  What am I doing wrong?

    You need to provide a valid client ID and secret pair.

    Sign-in to the API Developer Portal, select Apps then Add App.
    When you finish adding an app, the client ID is the 'Consumer Key' and client secret the 'Consumer Secret'.

    If you previously have added an app, then copy the Consumer Key and Secret and paste it into your OAuth token request.

  • "Access Denied" Errors

    If you are experiencing an "Access Denied" error displayed on a page within the USPS Developer, please try the following troubleshooting methods:

    • Clearing browser cache
    • Clearing browser cookies
    • Switch to your browsers "Incognito" mode
    • Switch to a different browser 
    • Reboot system and log back into the USPS Developer Portal

    If you are still experiencing issues, please reach out to APISupport@usps.gov. 

     

     

  • What APIs are included in the default product for my App?

    The default product includes OAuth, Addresses, Domestic Pricing, International Pricing, Locations, Service Standards, and Shipping Options, each with a quota of 60 calls per hour. To get started with APIs not included in the default or to request a quota increase, USPS will need additional information. Please complete the form here: Registration for API Access Form 

  • Where to find USPS APIs Release Notes

    USPS APIs Release Notes can be found on USPS PostalPro website. The Release Notes are updated frequently to notify integrators of forthcoming updates across the USPS APIs catalog. Please view the Release Notes documentation here: https://postalpro.usps.com/usps-apis-releases. 

  • I received a ‘429' exceeded quota limit error. How do I resolve this?

    If you have exceeded the quota limit of API calls per hour, please complete and submit the Registration for API Access Form to get access to additional APIs or get a higher quota limit. Note: You must be logged in to your USPS Developer account in order to submit the form. Any incomplete or missing information will delay your request.

  • What is the difference between an API and an API Product?

    USPS APIs are bundled into consumable packages called API products.
    Each API product limits APIs access by time, scope, and quota.
    Review the API product documentation to choose the API products that meet the end-user activity and usage needs of your application.
    Are you performing a soft launch of your application?  Choose an API product with a limited duration. You may upgrade to a comparable API product later.
    Some API products are approved automatically upon request and others require administrative approvals in order to utilize their included APIs.

  • I’m not getting the expected response. Who do I contact?

    Please contact USPS at APISupport@usps.gov

  • Where do I go to request API keys?

    All USPS APIs utilize OAuth, an industry standard, to grant authorized access.

    You will be issued a Consumer Key and Secret when you 'Add an App' in the API Developer Portal.