Over the past few years, I’ve watched the rules around renting in England shift more than in any other period I can cover. The biggest change is the Renters’ Rights Act 2025, which takes full effect from 1 May 2026. One of its most practical consequences is that fixed-term tenancies are gone for new agreements — every tenancy is now periodic from day one. That means there’s no natural renewal point where you sit down and renegotiate the whole contract. Instead, mid-tenancy variations and addendums have become the main way to adapt a tenancy when circumstances change. If you’re a tenant or a landlord, understanding how these documents work is no longer optional. Here’s what you actually need to know.
If you’re currently renting or letting a property, the shift to periodic tenancies means you can’t just wait for the fixed term to end to sort out changes. A new partner moving in, a housemate leaving, or a rent adjustment all now require a formal variation or addendum. I’ve seen too many people try to handle these with a quick email or a handshake, and that’s where problems start. Getting the paperwork right from the beginning saves a lot of stress later. For a broader look at how tenancy structures work, you might find this guide on short-term vs long-term leases useful context.
What a tenancy addendum actually is
The most important thing to understand is that an addendum doesn’t replace your tenancy agreement — it sits alongside it and changes specific terms. Under the post-RRA 2025 framework, you can’t just agree a change verbally or by text message. A written variation signed by both parties is the minimum requirement for most changes, and some changes — like rent increases — have their own strict legal process. The key term here is “variation deed,” which is the formal document used to amend a tenancy without ending it.
What I’d do if I were a tenant facing a change: I’d ask the landlord for a written variation, not just permission. If a new partner is moving in, I’d want them added to the tenancy so they have proper rights and shared liability. If I’m a landlord, I’d never accept a verbal agreement to change the rent — the Form 4 process exists for a reason, and skipping it leaves you unable to enforce the increase. For more on how shared living arrangements work in practice, this article on navigating shared living covers the common friction points.
Why getting the paperwork wrong costs you
The consequences of an informal variation can be surprisingly expensive. Take rent increases: before the RRA 2025, some landlords and tenants agreed a rent rise by email and it was enforceable. Now, if you don’t use Form 4 with two months’ notice, the increase is simply invalid. The tenant can refuse to pay the higher amount, and the landlord has no legal route to collect it. I’ve seen cases where landlords lost thousands of pounds because they thought a quick message was enough.
Consider a scenario where a tenant in a houseshare wants to leave. If the remaining tenants just let them go without a formal deed of variation, the departing tenant remains jointly liable for rent and obligations. If the remaining tenants stop paying, the landlord can pursue the person who moved out months ago. That’s a real risk that a simple addendum would have solved. The research on mid-tenancy variations makes clear that the cleanest route is a deed of variation signed by all parties.
What I’d do: if I were a tenant leaving a joint tenancy, I’d insist on a deed of variation that explicitly releases me from future liability. I’d also check that the deposit protection scheme has been updated to reflect the change. If I were a landlord, I’d never let a tenant leave without a signed deed — the ongoing liability risk isn’t worth it. For a deeper look at how to handle shared tenancy situations, this guide on roommate lease agreements has practical advice.
Where people go wrong with addendums
The most common mistakes I see fall into a few clear patterns. Each one is avoidable if you know what to look for.
Treating a rent increase as a simple agreement
Under the RRA 2025, rent review clauses in tenancy agreements can no longer be used. The only legal way to increase rent is through the Form 4 / section 13 procedure. That means two months’ notice, the prescribed form, and a maximum of one increase every 52 weeks. A tenant who receives a rent increase by email can simply ignore it — it has no legal effect. The Landlords Guild guidance on the new forms confirms that the Form 4A is the only valid route.
Letting a tenant leave without a deed of variation
This is the mistake that causes the most long-term problems. When one tenant in a houseshare moves out, the remaining tenants often just carry on paying the rent. But the departing tenant remains legally liable for the tenancy. If the remaining tenants default six months later, the landlord can pursue the person who left. A deed of variation signed by all parties — departing tenant, remaining tenants, and landlord — releases the departing tenant from future liability. Without it, the liability continues indefinitely.
Adding a new occupier without updating the tenancy
When a new partner moves in, many tenants simply let them live there without adding them to the agreement. That makes the new person a “permitted occupier” — they have no direct legal relationship with the landlord. If the relationship ends, the new partner has no right to stay. If they stop paying rent, the landlord can only pursue the original tenant. Adding them to the tenancy via a deed of variation creates joint and several liability, which is cleaner for everyone. It also requires referencing and deposit handling, but it’s worth the effort.
Giving the Information Sheet too early
The RRA 2025 requires landlords to give tenants a prescribed Information Sheet about the changes. The deadline is within one month of the commencement date — which is 1 May 2026. A county court decision in Siddeeq v Alaian held that similar prescribed information couldn’t be given before the relevant date because of the wording in the legislation. The safest approach is to provide the Information Sheet between 1 and 31 May 2026 — no earlier and no later.
→ Scroll right to see all columns
| Variation Type | Required Document | Key Rule |
|---|---|---|
| Rent increase | Form 4 / section 13 notice | 2 months’ notice, once per 52 weeks |
| Adding a tenant | Deed of variation or new tenancy | New tenant must be referenced and given Information Sheet |
| Removing a tenant | Deed of variation | Releases departing tenant from future liability |
| Term change (e.g. pet permission) | Written variation signed by both parties | Must be in writing to be enforceable |
What I’d do: if I were a landlord, I’d set a calendar reminder for 1 May 2026 to prepare the Information Sheet and serve it within the month. If I were a tenant, I’d never accept a verbal agreement to change the tenancy — I’d ask for everything in writing. For more on how to spot problems in tenancy documents, this article on spotting lease fraud covers the warning signs.
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How to handle the most common addendum situations
Here’s a practical guide to the three situations where you’re most likely to need an addendum, with the exact steps to follow.
Adding a new tenant to an existing tenancy
When a new partner or family member moves in, you have two options. The simpler route is to let them occupy as a permitted occupier — they have no direct legal relationship with the landlord, and the existing tenant remains solely liable. The cleaner route is to add them to the tenancy via a deed of variation or a new tenancy agreement. If you choose the second route, the new tenant needs to be referenced, given the prescribed Information Sheet, and any additional deposit must be handled and protected. The deed of variation must be signed by the existing tenant, the new tenant, and the landlord. Once signed, both tenants become jointly and severally liable for rent and obligations.
- 1Decide between permitted occupier or full tenantIf the new person is transient or not paying rent, permitted occupier is simpler. If they’re sharing financial responsibility, add them to the tenancy.
- 2Reference the new tenantRun credit and reference checks. Provide them with the prescribed Information Sheet about the RRA 2025 changes.
- 3Prepare and sign the deed of variationThe deed must name all parties and state that the new tenant is added to the tenancy. All parties sign. Update the deposit protection scheme registration.
Removing a tenant from a joint tenancy
This is the situation where getting it wrong has the longest tail. If a tenant in a houseshare wants to leave, the cleanest approach is a deed of variation that releases them from future liability. The deed must be signed by the departing tenant, all remaining tenants, and the landlord. It should state the date from which the departing tenant is released and confirm that any unpaid sums up to that date remain their responsibility. The deposit protection scheme registration must also be updated to reflect the change. Without this deed, the departing tenant remains jointly liable for rent and obligations indefinitely.
- 1Confirm the departing tenant’s final rent and billsCalculate any unpaid rent or bills up to the departure date. The deed should state these are the departing tenant’s responsibility.
- 2Draft the deed of variationThe deed names all parties, states the departing tenant is released from future liability, and confirms the remaining tenants continue the tenancy.
- 3Sign and update the deposit schemeAll parties sign. Notify the deposit protection scheme of the change. The departing tenant’s share of the deposit is either returned or transferred.
Handling a rent adjustment
Under the RRA 2025, rent increases must follow the Form 4 procedure. The landlord serves Form 4 with at least two months’ notice, and the increase takes effect at the start of a rental period. The tenant can refer the increase to the First-tier Tribunal, but the Tribunal cannot now set a rent higher than the landlord proposed. Rent reductions — where both parties agree the rent should go down — do not need Form 4. They can be handled by a simple written agreement. The key distinction is that Form 4 exists to protect tenants from unilateral increases, not to constrain agreed reductions.
What happens with pet requests from 1 May 2026
From 1 May 2026, tenants have the right to request a pet. Landlords cannot unreasonably refuse and must give written reasons if they do. If a landlord agrees, the tenancy needs a variation to permit the pet. This is a term change — a written variation signed by both parties is sufficient. It doesn’t need a deed or Form 4. The variation should specify any conditions, such as professional cleaning at the end of the tenancy or an additional deposit for pet damage. For landlords letting to full-time students, ground 4A allows recovery of possession at the end of the academic year, subject to prior written notice to the tenant by 31 May 2026.
Frequently asked questions
Can I use a simple email to change the tenancy terms? ▾
What happens if a tenant leaves a houseshare without a deed of variation? ▾
Do I need a lawyer to draft an addendum? ▾
Can a landlord increase rent more than once a year? ▾
What if the landlord refuses to sign a deed of variation? ▾
When should I give the Information Sheet to my tenant? ▾
Final thought
The shift to periodic tenancies and the stricter rules around variations mean that getting the paperwork right is more important than ever. My advice is simple: never rely on a verbal agreement or a quick email for any change to a tenancy. Use the prescribed forms for rent increases, use a deed of variation for tenant changes, and always get everything in writing. If this was useful, you might also want to read Understanding Utilities Included in a Lease When Renting an Apartment.
Sources and Further Reading
Rental Application Secrets: Boost Your Chances of Landing That UK Flat — Practical tips for tenants navigating the application process in the current market.
Understanding Rental Yield: A Guide for Renters in the UK — Explains how rental yield affects what you pay and what landlords expect.
Mid-Tenancy Variations and Addendums. Tenancy Agreement Service, 2025.
Renters’ Rights Act 2026 Information Sheet and Forms. Landlords Guild, 2025.
