Yes, but federal law requires all firearm transfers to be completed through a licensed FFL at the point of delivery. This means online firearm sales are processed as transfers — the customer pays online, the firearm ships to their local FFL, and that FFL completes the 4473 and NICS check. As the selling FFL, you handle the shipping and outbound A&D disposition. Your POS should manage the online order, inventory deduction, and A&D entries in one workflow.
