What happens: If you've signed a tenancy but not moved in when 1 May 2026 arrives, your situation is treated as an existing tenancy. When you move in, the fixed end date will not lock you in. The agreement runs as a month-to-month tenancy. Even if your agreement shows an end date in June or July, it will not end automatically on that date. From 1 May 2026 it behaves as a rolling monthly tenancy, so you will usually need to give at least two months' written notice ending on a rent day if you want to leave around the end date shown in your current fixed term agreement.
Joint tenancies: From May 1st, individuals in a joint tenancy will gain the right to bring it to an end if they tell the landlord giving the landlord 2 months' notice. If you are on a joint contract and 1 person gives notice to quit, technically that person has given notice for the whole house to be out the property in 2 months' time. This is not ideal if some of the group want to continue to live there. In this situation you are recommended to speak to your landlord and your fellow tenants as soon as possible to see if it's possible for the rest of the group to stay and under what terms. The landlord will then have the option to negotiate with the remaining tenants.
For more information on giving notice see this article from Unipol:https://www.unipol.org.uk/advice/renters-rights-act-2025-advice-for-students/giving-notice-joint-and-individual-tenancies/
Rent in advance: Because you signed before 1 May 2026, the new rent-in-advance cap doesn't affect the agreement you've already entered into — even though you haven't moved in yet. If your contract required several months' rent upfront, the landlord can still enforce that. But once your tenancy begins and converts into a periodic tenancy (as it will automatically after 1 May), the landlord cannot ask for any further rent in advance beyond one month at a time.
For more information on rent payment changes see this article by Unipol:https://www.unipol.org.uk/advice/renters-rights-act-2025-advice-for-students/rent-payments-post-renters-rights-act-2025/
Everything else: All the rules from Scenario 1 above apply to you once you move in. If you are living in an HMO and have a fixed term contract, its fixed term nature disappears. As long as the landlord writes to you and says they intend to use “Ground 4A”, the landlord will need to give you notice to evict you between June and September. During the transitional period (notices served between 1 May and 31 July 2026), this is two months' notice rather than the standard four months. You also gain the right to end the tenancy yourself by giving at least two months' written notice that ends on a rent day - the same rule as in Scenario 1.