I was told by the ATF that when the location of NFA item(s) change a 5320-20 has to be completed. I had to fill out this form even though I had only moved four blocks from the address on the original Form 4. They want to know where the weapon(s)/item(s) is located.
The 5320-20 form: Application To Transport Interstate or to Temporarily Export Certain NFA Weapons is in fact a permission request to remove the item(s) from one location and transport to another. A high percentage of these 5320-20 forms are filled out and approved by the ATF long after the item(s) have already been moved.