Conn. Gen. Stat. § 12-408f

(1) “Referral” or “refer” means the transfer by a referrer of a potential purchaser to a seller who advertises or lists tangible personal property for sale on or in the referrer's medium; and

(2) “Referrer” means any person who (A) contracts or otherwise agrees with a seller to list or advertise for sale one or more items of tangible personal property by any means, including an Internet web site and a catalog, provided such listing or advertisement includes the seller's shipping terms or a statement of whether the seller collects sales tax, (B) offers a comparison of similar products offered by multiple sellers, (C) receives commissions, fees or other consideration in excess of one hundred twenty-five thousand dollars during the prior twelve-month period from a seller or sellers for such listings or advertisements, (D) refers, via telephone, Internet web site link or other means, a potential customer to a seller or an affiliated person of a seller, as described in subparagraph (C) of subdivision (15) of subsection (a) of section 12-407 , and (E) does not collect payments from the customer for the seller. For purposes of this subdivision, “shipping terms” does not mean a seller's mere mention of general shipping costs in the seller's own listing or advertisement.

(b) Each referrer shall, to the extent not prohibited by the Constitution of the United States:

(1) Post a conspicuous notice on or in such referrer's medium that informs consumers (A) that sales or use tax is due from Connecticut purchasers on certain purchases, (B) that the seller might not collect and remit sales tax on a purchase, (C) that Connecticut requires Connecticut purchasers to file a use tax return if sales tax is not imposed at the time of the sale by the seller, (D) of the instructions for obtaining additional information from the Department of Revenue Services regarding the remittance of sales and use taxes on purchases made by Connecticut purchasers, and (E) that such notice is being provided pursuant to this section;

(2) Provide, not later than January 1, 2020, a quarterly notice to each seller to whom such referrer transferred during the previous calendar year a potential purchaser located in this state that contains (A) a statement that Connecticut imposes a sales or use tax on sales made to Connecticut purchasers, (B) a statement that a seller making sales to Connecticut purchasers must collect and remit sales and use taxes to the Department of Revenue Services, and (C) instructions for obtaining additional information regarding the Connecticut sales and use taxes from said department.

(c) Not later than January 31, 2021, and annually thereafter, each referrer shall submit a report electronically, in a form and manner prescribed by the Commissioner of Revenue Services, to the commissioner that contains (1) the name and address of each seller who received a notice pursuant to subsection (b) of this section in the calendar year immediately preceding, and (2) the name and address of each seller for which the referrer knows that such seller (A) listed or advertised such seller's tangible personal property on or in such referrer's medium, and (B) collected and remitted Connecticut sales and use taxes.