A licensee may transfer a firearm to a transferee as soon as he or she receives a “proceed” from NICS (assuming that the transaction would be in compliance with state law).

However, if the licensee does not receive a final “proceed” or “denied” response from NICS, he or she must wait until 3 business days have elapsed prior to transferring the firearm.

[18 U.S.C. 922(t); 27 CFR 478.102(a)(2)]