This is how you add a second tenant to a lease:
- Open your Lease.
- Click on the Add people dropdown
- Choose if the person is a tenant, other contact or guarantor and then choose which relation they are. a New contact box will open up to fill with their details.

- To split the rent between the two tenants check the Split Rent box.

This is how to locate any contact in the system who is not the primary leaseholder but either a guarantor or another party associated with the lease: