What happened?

Vertex O Series (OSC) has a number of options for parsing addresses. The settings in your deployment of OSC define this.

If you do not specify addresses correctly in your requests to the API, you may get some messages that may not apply to the situation directly and may be confusing as a result. For example:

{
    "success": false,
    "errors": [
        "Invalid country code XX. Expecting an ISO Country Code - Alpha 2 (e.g., US).",
        "[O-Series error] Unknown country. Expecting an ISO Country Code - Alpha 3 (e.g., USA), or a well-known country name (e.g., United States of America). (country=XX)"
    ],
    "requestId": "02e49003-a556-45ff-91b2-c265f8026116"
}

How to fix it?

Ensure that you use valid address information that is compatible with your OSC configuration, as described in the Addresses topic.