Question - Even though there are still several months of their tenancy left, we both feel it would be better if they moved on. Can we agree to end the tenancy early?
Answer - The terms of the tenancy agreement can be varied at any time by agreement with your tenant. So in principle you could bring your tenancy to an end before the original expiry date under the lease.
You should ensure that any agreement is recorded in writing and signed by both parties, setting out a mutually convenient date by which the lease will terminate and your tenant will move out.
If your tenant refuses to end the tenancy early, or agrees, but then fails to move out by the expiry of the lease, you would have to raise a court action and obtain a decree for possession of the property to lawfully remove them.
Before going to court, certain statutory notices need to be served on residential tenants under the Housing (Scotland) Act 1988, up to two months before raising a court action. For assured tenancies, a notice in terms of Section 19 (an "AT6 Notice") needs to be served, relying on one or more of the grounds set out in Schedule 5 to the 1988 Act. If the tenancy is a short-assured tenancy, you would also be entitled to recover possession under Section 33 of the 1988 Act - in which case, a "Section 33 Notice" should be served on the tenant.
While you don't need to serve these notices to be able to terminate the tenancy early - they are required only if things turn sour - it's still worth serving them at the same time as signing any agreement to bring the lease to an end. That way, the notice period under either or both notices can start to run, and you would not need to wait another two months to raise a court action if the tenant ultimately refused to move out by the termination of the lease.