Invoice_Search API request not returning any invoices for specific client

[martinprice]

I think @samppatel means the API sandbox rather than a sandbox account:

Testing the API - Beginners Guide

The QuickFile API comes complete with a sandbox test environment where you can experiment with various combinations of your own hand crafted JSON/XML. You really don’t need much programming experience to work with the sandbox, just a basic understanding of how JSON or XML is structured, and there are plenty of examples to get you started. One of the advantages of testing in the sandbox is that it will automatically set your authentication headers. The AccNumber , MD5Value and ApplicationID will…