Prerequisites

You can only deactivate active lease-outs as long as no actual records in the cash flow exist, or any existing records have been reversed.

Procedure

When editing an active lease-out, choose  Lease-out Deactivate and save.

Result

The status of the lease-out changes from ACTV (active) to CRTE (created).

Now you can enter, say, a new master tenant which is not possible within active lease-outs.