I'm an e-commerce business. My business is located physically in Mass. I sell nation-wide.

I either buy inventory from suppliers nation-wide and sell to homeowners nation-wide, or suppliers drop-ship direct to my homeowner customers, nation-wide and I never touch the inventory. My issue does NOT concern paying Mass Sales Tax on sales made to customers in Mass. That's the physical store law, whatever.

Question: Mass has reciprocity with most states. In this case a supplier in North Carolina asks for their tax exemption form. I don't know how to handle it. Mass apparently has a "partial reciprocity" with North Carolina, seen at: TIR 03-1: Exemption From Massachusetts Use Tax...

How do I manage this issue?