From Prince Law Offices, P.C.:

It’s no secret that ATF told at least one FFL they need to run a NICS check on trustees picking up NFA firearms on behalf of a trust. In a letter addressed toDakota Silencer, ATF explained:

The term “person” is defined by the GCA at 18 U.S.C. § 921(a)(1), to include “any individual, corporation, company, association, firm, partnership, society, or joint stock company.”

ATF has interpreted the GCA exception in sections 922(t)(3)(B) and 478.102(d)(2) to mean that firearms transfers are exempt from a NICS check when they have been approved under the NFA to the person receiving the firearm. Unlike individuals, corporations, partnerships, and associations; unincorporated trusts do not fall within the definition of “person” in the GCA.

Because unincorporated trusts are not “persons” under the GCA, a Federal firearms licensee (FFL) cannot transfer firearms to them without complying with the GCA. Thus, when an FFL transfers an NFA firearm to a trustee or other person acting on behalf of a trust, the transfer is made to this person as an individual (i.e., not as a trust). As the trustee or other person acting on behalf of the trust is not the approved transferee under the NFA, 18 U.S.C. 5812, the trustee or other person acting on behalf of a trust must undergo a NICS check. The individual must also be a resident of the same State as the FFL when receiving the firearm.

There is a lot of technical legal speak in this post but it is fascinating how the government has spun such a tangled web of laws that may actually cancel out or contradict one another.