MineralTree supports attaching supporting documents to existing invoices.
Documents that are located in your inbox are eligible.
If the document you want to add is not yet in your inbox, you can add the desired document by going to your inbox and selecting the up arrow on the left hand corner.
A popup will display, and you can select the document from your computer that you would like to upload.
Once your document is uploaded, go to the Invoices tab and click on the desired invoice number.
Once the invoice is open, select the Documents tab.
From there, you can select the Actions dropdown button and click on 'Attach Additional Documents.' This will allow you to select the document you uploaded.