Yes — this is a standard, TREC-supported move
A seller isn't stuck waiting to see if a buyer performs before lining up a second option. TREC publishes a form for exactly this situation: the Addendum for "Back-Up" Contract (TREC No. 11-9), effective 05-04-2026 and replacing the prior 11-8 version. It attaches to a second, fully executed contract on a property that already has a live first contract, so the two deals don't legally conflict.
The back-up contract is real from day one — just not active
Paragraph A of TREC 11-9 says the back-up contract is binding upon execution. The back-up buyer still delivers earnest money and any option fee under Paragraph 5 of that contract, plus a negotiated additional earnest money and additional option fee within a set number of days after the "Amended Effective Date" (more on that below). But Paragraph G makes clear the whole thing is contingent on the first contract terminating — and while that contingency is in place, neither the seller nor the back-up buyer has to actually perform.
What happens when the first deal falls through
If the original contract terminates, the seller has to tell the back-up buyer right away. That notice is now its own form: TREC No. 62-0, the Seller's Notice to Buyer of Removal of Contingency Under Addendum for "Back-Up" Contract, also effective 05-04-2026. It states three things — the first contract is terminated, the contingency in Paragraph G is removed, and the date on the notice becomes the back-up contract's Amended Effective Date. That's the date the back-up contract's own option period, financing deadline, and closing timeline start counting from — not the date it was originally signed.
For the full paragraph-by-paragraph mechanics — the additional earnest money timing, weekend rollover, and how the buyer's unrestricted termination window interacts with the Amended Effective Date — see the full Texas Back-Up Contract Addendum guide.