@MarieHuggins the third party policy applies to people being there during the sit . If the home owner invites you to come a day early for a handover ; this isn’t breaking the third party policy . It happens quite often when the HO has an early departure on the first day of the sit .
You don’t have to accept this offer - you can stay nearby at your own expense ,if they have an early departure or with their agreement arrive after they have left . This is something to be discussed before committing to a sit .
It has been discussed here Do you host sitters who are coming from a distance?