No, you will not be able to modify the Source Journal Code for transactions you import.  

You could create a UDF for the AP invoice header table to indicate how it was entered.  Default it to "AP" manual entry and import a VI if imported.

Thank you for your quick response,

If I understand you correctly, the suggestion is to add a UDF and default it to AP.  Then, for this specific VI import, add a different entry for that UDF.  I'll consult with the client...thank you for the optional solution.

I usually do a checkbox for things like this as an imported flag, set to "Y" during the import, then flow that to history and displayed on the inquiry screen.  A text UDF makes sense when you have more than a Y/N designation.

Many ways to solve the problem but it is important to understand the issue.  Why is it important to know how the invoice was entered.  Tracking $$'s in the GL or total number of invoices entered?  Something else?  

This is a slow rollout of converting vendor invoices to a third-party clearinghouse.  Client wants a way to keep the information coming from the imports separate until all vendor invoice transactions have been migrated to the third-party.

If a different Sage login is used for manual AP entry (vs the imported invoices) you might be able to look at UserCreatedKey in invoice history to tell the invoices apart (without a UDF).

I'll look into that, Kevin...thank you for the "outside-of-the-box" ideas, I truly appreciate it.