This form serves two main purposes.  First, it confirms in writing that the tenant has given back all the keys to their rental unit near or at the end of their tenancy.  It’s a signed declaration by the tenant (accompanies with the keys of course) that makes it clear that the keys have transited to the landlord/property manager. The second purpose is to confirm the tenant no longer requires access to the unit.  This is especially important if the tenant has fully vacated the premises before the official end of the rental term.  Technically, they still enjoy legal access right up to that last day of their lease or agreement.  However, with this form, they unofficially forfeit their access to the rental unit if time still remains in the term.  Passing keys back is symbolic and practical in confirming an end to tenancy.