If a tenant wants to leave early, where do I stand

A. This is a case for individual consideration. If your tenant wants to leave because his circumstances have changed, he can no longer afford the rent, then it might be wise to release him but retain some of the security deposit to cover costs. If he just fancies a change, then he is still accountable for the remainder of the rental period for the term of the agreement.

There are informal ways around this: he might be able to find a replacement tenant to cover the interim period. If the rental market is buoyant, you may be able to find another tenant quickly in any case and can use any “spare” time to make repairs, undertake maintenance, etc.