When a trust or other legal entity (including corporations, married couples jointly registering a firearm, etc) must submit ATF Form 5320.1 (“Form 1”), Application to Make and Register NFA Firearm, as the maker, or is identified as the transferee on ATF Form 5320.4 (“Form 4”), Application to Transfer and Register NFA Firearm (Tax-Paid), or ATF Form 5320.5 (“Form 5”), Application to Transfer and Register NFA Firearm (Tax-Exempt), they are not able to submit individualy identifying information for purposes of a background check. As a result, ATF Form 5320.23 is required for any responsible person (as defined in 27 CFR 479.11) who is part of such trust or other legal entity. Forms 1, 4, and 5 are required under the National Firearms Act (NFA).