How to check for invoice duplication in Sage 300 using Access
Overview
Log into the server Sage 300 is installed
Verify the ODBC Setup for the Sage 300 instance
Open ODBC Data Source Administration (32-bit) from the Windows Search by typing in odbc. Once open go to the System DSN tab. It will look like the below image.
Open the Data source you think is attached to the specific Sage 300 company to verify the source path. It will have a driver called Timberline Data. It will look like the below image when opened.
When you have the proper Data source setup or connected you will want to open Access to verify the Sage 300 Data has a duplicate.
Open Access and create a new Blank Database to query Sage 300
Open the Access app on the Sage 300 server. Create a new Blank database. It will look like the below image.
Once opened name your new DB file and click create. It will look like the below image.
Once your new Access DB is open, close the table it opens by default by right clicking on the tables tab and selecting Close from the dropdown. It will look like the below image.

Now that the table is selected close all open tabs and then go the the Access Create tab and then select Query Design from the menu. It will look like the below image.
Once you click run you will likely be prompted to choose the ODBC again, it will look like the below 2 images.
This will now display all the Invoices that match the number you queried for. It will look like the below image.