Setting up the USPS Api

I’m trying to set up to use the USPS shipping calculator. (ended up losing all of my levels of shipping i had entered when I decided to see what the USPS had to offer) Anyway I applied for the USPS API and received the information back from them. What I don’t know how to do is to create the XML string that they require you to test before you can go live.

Thanks in Advance

  • aecnu
    • WP Unicorn

    Greetings Dean,

    It is my opinion that you would want to run a fake transaction in Market Press which includes a purchase and shipping which in turn would actually test USPS with an xml file.

    Please advise if this does not work by simply check marking the not resolved box below and submit any errors or symptoms that could possibly help us figure out any issues.

    Thank you for being a WPMU Dev Member!

    Cheers, Joe

  • Dean Kaus
    • The Bug Hunter

    I tried to enter an order and take it through the process. It does get to the paypal page however it doesn’t add shipping. Also the USPS box in the cart checkout doesn’t offer any options of which i selected.

    As per USPS instructions I’m supposed to create a user id and xml string which I have no clue how what information to put in this string.

    I’ve pasted below the API instructions from the USPS. (less my username and password)

    Your Web Tools User ID, shown above, is required to test and integrate USPS Web Tools APIs. With this ID, you may begin sending calls to the test

    server. Depending on the API, the address to the test server is either or Use this information in combination with your User ID and your XML string to send a request to the USPS servers. For more details, refer to the programming guides (located at for the specific API you are integrating.

    A sample test request would look like: “[API_Name]&XML=[XML_String_containing_User_ID]”

    When you have completed your testing, email the USPS Internet Customer Care Center (ICCC). They will switch your profile to allow you access to the production server and will provide you with the production URLs.

  • Dean Kaus
    • The Bug Hunter

    So I never heard back from anyone on this matter so I called USPS. After 40 minutes on hold discovered that if using Marpetpress you don’t have to run any tests as they have apparently already taken care of this process when they wrote the code.

    So all you need to do is either call 1-800-344-7779 and let them know you are using Marketpress Plugin and they will transfer you to their production server. (only took 3 minutes after I talked to someone)

    Or you can email them at.

    In either case have the email you registered with the USPS API request and your Username that they emailed you.

    Hope this helps everyone!

  • aecnu
    • WP Unicorn

    Greetings Dean Kaus,

    Sorry for the delay here in a reply, it appears this ticket somehow got buried in the back of the ticket system and while rummaging through tickets I found this one again.

    Please advise on where we are currently at with the issues of this ticket.

    Are we connecting with USPS yet?

    Are we getting the shipping amount with purchase price for PayPal checkout?

    Please advise.

    Cheers, Joe

  • Dean Kaus
    • The Bug Hunter

    @aecnu Sorry I thought that my previous post (the one just before your response) explained what needed to be done in order to complete the USPS setup.

    I did and do have the USPS working properly now.

    I don’t recall but I may have also started a new thread or topic explaining that the email received from the post office instructing about the testing process was not needed. All that is needed once you have the credentials they email you is to either call them at 1-800-344-7779 and request to be transferred to their production server. You can also email them with the same request at

    PS I just noticed the support topic box below and I guess that I should have marked it as resolved.


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