How to raise the rent legally in 2026

Since the Renters' Rights Act commenced on 1 May 2026 there is one lawful way to put the rent up on a residential tenancy, and that is a section 13 rent increase served on Form 4A. Once in any twelve month period. At least two months' notice. If the tenant believes the new figure sits above open market rent, they can ask the tribunal to decide it instead of you. Everything else, the conversation at the door, the letter that says "as per clause 4 of your agreement", the annual uplift you have applied for a decade without anyone objecting, no longer does the job.

That change caught a lot of landlords out over the summer. It is not a small procedural tweak. It sits alongside the abolition of Section 21 and the conversion of every assured shorthold tenancy into an assured periodic one, and if you have not read through the wider changes the Act brought in for landlords, the rent increase rules will feel arbitrary until you see the rest of the picture.

The rules, short version

• One increase per tenancy in any twelve month period.
• Form 4A, the prescribed form. Not a letter, not an email, not your own template.
• Minimum two months' notice before the new rent starts.
• It applies to assured periodic tenancies, which since 1 May 2026 means effectively every residential tenancy you hold.
• The tenant can apply to the First-tier Tribunal to challenge an increase they say is above open market rent.

The government's overview of the Act for landlords sets out the position, and the Information Sheet you were required to give existing tenants by 31 May 2026 explains the same rules from the tenant's side. Worth reading both, because your tenant may well have read the second one.

Step one: check the date of your last increase

Before you serve a section 13 rent increase, find out when the rent last went up and how. If you increased it informally in the last twelve months, you have a problem, because that informal increase may not be valid and the clock on it may not run the way you assume. If in doubt, treat the last properly served notice as your reference point and get advice from a solicitor before serving another.

The twelve months runs from the date the last increase took effect, not the date you served the notice. Landlords get these two dates mixed up constantly.

Step two: work out the market rent before you pick a figure

This is the step most people skip, and it is the one that decides whether the increase survives. The test at tribunal is open market rent for that property, in that condition, in that area. Not what you need to cover the mortgage. Not what the property next door achieved three years ago.

Build a small file of evidence before you commit to a number:

• Advertised rents for the same property type and bedroom count, within a tight radius. Balby is not Bessacarr, and a tribunal will know the difference.
• Similar condition, similar furnishing standard, similar EPC band. A refurbished two bed does not evidence the rent on a tired one.
• Screenshots with the date visible, saved as you go. Portal listings disappear.
• Ignore the outliers at both ends and look at where the bulk of the comparable listings sit.
• Note anything about your property that pulls the figure down as well as up. Parking, no parking, garden, top floor with no lift.

Advertised rents are a proxy, not proof of what was achieved, so use several rather than one. If you are a member of a landlord association, or you use an agent who is a Propertymark member, you should be able to get a view on achieved rents locally rather than asking prices alone.

Then pitch slightly under what your evidence supports. An increase that lands just below market is very hard to argue with. An increase that lands just above it invites a challenge you may lose.

Step three: complete Form 4A properly

Form 4A is the prescribed notice of a proposed new rent. Get the mechanics right:

Name every tenant on the agreement, spelled as they appear on it. Give the full property address including the postcode. State the current rent and the proposed new rent, with the period they relate to (per calendar month, per week, whichever your agreement uses). Put in the date the new rent is to start, and count your two months carefully from the date of service, not the date you filled the form in.

The start date has to line up with the rental period. If rent falls due on the 5th, the new rent starts on a 5th. Picking the 1st because it is tidier is the sort of small error that makes a notice defective.

If you are unsure whether your tenancy is periodic, or when its periods actually begin and end, that matters here. We covered how periodic tenancies work now that fixed terms have gone in more detail, and the rental period is the bit that governs your dates.

Step four: serve it and record how you served it

Serve the notice in a way you can evidence. Post it and keep proof of posting, or hand deliver it with a dated photograph, or both. Keep a copy of exactly what you sent. If the increase is ever tested, the question will not be whether you served it, it will be whether you can show you served it, and on what date.

Then put the start date in your diary along with a note to check the rent actually changes on the standing order.

If the tenant challenges it

The tenant can apply to the tribunal for a determination of the open market rent. There is a deadline for that application and it falls before the new rent is due to begin, so check the current guidance rather than relying on how the old system worked.

If the application goes in, the tribunal decides what the open market rent for the property is. That determination is what you get, whatever you asked for. This is why the evidence gathering at step two is not optional. Turning up with a spreadsheet of dated comparable listings is a very different position from turning up with an opinion.

Most challenges never happen. Tenants who receive a well evidenced, slightly under market increase with proper notice usually pay it. The ones that get challenged are almost always the ones that were pitched hopefully.

Where landlords get this wrong

Agreeing an increase informally

You speak to the tenant, they say fine, the standing order changes. It feels sensible and it is the single most common mistake we see. Without Form 4A and two months' notice, you may have no enforceable new rent, and you have arguably used up your one increase for the year on something that does not stand up. Do it properly even when the tenant is agreeable.

Relying on an old rent review clause

Plenty of pre 2026 tenancy agreements contain an annual review or index linked uplift clause. Those clauses were written for a tenancy regime that no longer exists. Do not assume a clause in an agreement signed in 2023 gives you a route around the section 13 rent increase rules. If you think your agreement is an exception, that is a question for a solicitor, not for a template.

Getting the notice date wrong

Two months means two clear months before the new rent starts, and the start date has to fall at the beginning of a rental period. Miscount by a few days and the notice is defective. The tenant does not have to point it out at the time. It can surface much later, when it is far less convenient.

Pitching above market and losing at tribunal

Ambitious increases cost more than the money. You lose the increase you wanted, you have used the annual opportunity, and you have a tenant who now knows exactly how the challenge process works. A modest, defensible increase applied every year usually produces more rent over five years than one aggressive attempt that gets knocked back.

Before you serve the notice

Check three things: when the rent last increased and by what route, what comparable properties are actually advertised at right now, and whether your rental period dates line up with the start date you have in mind. If any of those are unclear, sort them out before the form goes out rather than after.

We handle rent reviews, Form 4A service and the evidence behind the figure as part of managed lettings across Doncaster, Rotherham, Sheffield and Barnsley, and rent reviews are included rather than billed separately, which you can see on our fees page. If you would rather run it yourself, run it to the letter. The process is not difficult, but it is unforgiving about dates.