You can choose if a tenant contact record is required to update a Listing to Leased status.
To do this, follow the below steps:
Navigate to Settings located in the hamburger menu.
Scroll down and expand the Listings section on the right hand side.
There is a toggle for you to specify:
Always require Tenant when marking Listing to Rented?
If this is on, listings in your office will always require a tenant to be added to the Lease listing when updating the listing to Leased.