Things that can result in the "presumption" that a person is engaged in the business of dealing firearms. Emphasis added.
A person shall be presumed to have the intent to predominantly earn a profit from the sale or
disposition of firearms in civil and administrative proceedings, absent reliable evidence to
the contrary, when the person—
(1) Advertises, markets, or otherwise promotes a firearms business (e.g.,
advertises or posts firearms for sale, including on any website, establishes a website for
offering their firearms for sale, makes available business cards, or tags firearms with
sales prices), regardless of whether the person incurs expenses or only promotes the
business informally;
(2) Purchases, rents, or otherwise secures or sets aside permanent or temporary
physical space to display or store firearms they offer for sale, including part or all of a
business premises, table or space at a gun show, or display case;
(3) Makes or maintains records, in any form, to document, track, or calculate
profits and losses from firearms purchases and sales;
(4) Purchases or otherwise secures merchant services as a business (e.g., credit
card transaction services, digital wallet for business) through which the person makes or
offers to make payments for firearms transactions;
(5) Formally or informally purchases, hires, or otherwise secures business security
services (e.g., a central station-monitored security system registered to a business, or
guards for security) to protect business assets or transactions that include firearms;
(6) Formally or informally establishes a business entity, trade name, or online
business account, including an account using a business name on a social media or other
website, through which the person makes or offers to make firearms transactions;
(7) Secures or applies for a State or local business license to purchase for resale or
to sell merchandise that includes firearms; or
(8) Purchases a business insurance policy, including any riders that cover firearms
inventory.
Want to sell off dad's collection? If you rent a table at the local gun show, you'd better be ready to rebut the presumption that you are dealing in firearms.
Do you keep records of the purchase and sale prices of guns you no longer own? That's probably not a good idea unless you are willing and prepared to rebut the presumption created by that activity.
Note that this applies to civil and administrative proceedings, not directly to criminal cases.