Current states with special clauses or prohibiting the sale of Lower Receivers are:
Effective July 1, 2019, Washington state passed House Bill 1739, banning the sale of polymer 80% Lower Receivers. As of August 1, 2021, (to Bilson Arms knowledge) aluminum Lower Receivers are allowed to be purchased and sold.
February 14, 2020, New York passed S.7763-A/A9903, the Jose Webster Untraceable Firearms Act banning the sale and ownership of 80% Lower receivers.
Assembly Bill 857 requires all Lower Receivers have a serial number. Under this law, a resident must apply for a serial number via the California Department of Justice with the serial number being registered and engraved on the receiver or frame of your Lower Receiver.
On September 16, 2020, HB 2744, passed without the Governor’s signature makes it a Class C felony to purchase, manufacture, or otherwise obtain firearm parts for the purpose of assembling a firearm with no serial number. It also amends certain parts of previous firearm registration. (SD2)
Under Substitute House Bill 7219, Public Act 19-6, all Lower Receivers must be labeled with a serial number. The serial number is to be engraved on them before manufacturing. Further, no polymer receivers are allowed, and transferring “ghost guns” is prohibited except to law enforcement.
And finally, effectively banning all sales and ownership of Lower Receivers,
As of April 2016, per (former) Attorney General, Gurbir Grewel, New Jersey citizens are not allowed to sell or own Lower Receivers.