When tangible personal property is sold within the state and the seller is obligated to deliver it to a point outside the state or to deliver it to a carrier or to the mails for transportation to a point without the state, the retail sales tax does not apply: Provided, The property is not returned to a point within this state. The most acceptable proof of transportation outside the state will be:

1. (a) A waybill or bill of lading made out to the seller's order calling for delivery; or
2. (b) An insurance or registry receipt issued by the United States postal department, or a post office department's receipt; or
3. (c) A trip sheet signed by the seller's delivery agent and showing the signature and address of the person outside the state who received the delivered goods.

However, where tangible personal property pursuant to a sale is delivered in this state to the buyer or his agent other than a common carrier, the sales tax applies, notwithstanding that the buyer may subsequently transport the property out of this state.

(Authorized by K.S.A. 79-3618, K.S.A. 1971 Supp. 79-3602, 79-3606; effective, E-70-33, July 1, 1970; effective, E-71-8, Jan. 1, 1971; effective Jan. 1, 1972.)