It depends on how long the back-up buyer wants to stay in the back-up position. Some back-up buyers may want to have their contract terminate within days if the first contract doesn’t terminate early, while others may want to retain their back-up contract rights until after the last possible date that the first contract might close. If your client wants his back-up contract to last until or beyond the first contract’s closing date, you can also ask the listing agent to provide the first contract’s closing date.
Source: TAR
