16 CFR 437.7: Record retention.

To prevent the unfair and deceptive acts or practices specified in this Rule, business opportunity sellers and their principals must prepare, retain, and make available for inspection by Commission officials copies of the following documents for a period of three years:

(a) Each materially different version of all documents required by this Rule;

(b) Each purchaser's disclosure receipt;

(c) Each executed written contract with a purchaser; and

(d) All substantiation upon which the seller relies for each earnings claim from the time each such claim is made.