Figure: 34 TAC §3.438(b)(4)

Example:

Transactions
Date Buyer A Buyer B Buyer C
July 5 5,000 gal. 10,000 gal. 10,000 gal.
July 10 2,500 gal. 10,000 gal. 10,000 gal.
July 15 2,500 gal.     2,500 gal.
July 20 3,000 gal.    
 
The sale to Buyer A on July 20 is not taxable because it is the sale that caused the 10,000 gallon limit to be exceeded. The sale on July 10 to Buyer B is not taxable because it is the sale that caused the 10,000 gallon limit to be exceeded. The sale to Buyer C on July 15 is taxable because the 10,000 gallon limit was exceeded with the purchase on July 10.