Market rent evidence: how to back up a rent increase

Market rent evidence is the proof that your proposed rent matches what the property would let for on the open market on the same terms. It matters because if your tenant challenges a Section 13 notice, the tribunal sets the rent by that test, and it can't go above the figure you proposed.

What does "market rent" mean for a rent increase?

When a tenant applies to the First-tier Tribunal on form MR1, the tribunal works out the rent you "could reasonably expect if the property were let on the open market on the same terms". It may take the property's condition into account. The result is the lower of that figure and your proposed rent.

Three parts of that test shape the evidence you need:

Part of the test	What it means for your evidence
"Open market"	What a willing tenant would pay for a similar home now, not what you need to cover costs
"Same terms"	Compare like with like: furnished or unfurnished, bills included or not, the same rent period
Condition	The tribunal may look at the state of the property, so show it

Good evidence also helps before any challenge. A tenant who can see the figure is in line with the market has less reason to apply to the tribunal.

Market rent evidence that helps

There's no prescribed list. In practice, the most useful evidence is specific, dated and close to your property.

1. Comparable lets nearby. Homes of the same type, size and condition in the same area, let or advertised recently. Save a copy or screenshot of each advert with the date.
2. Your own recent lettings. If you've let a similar unit in the same building or street, the agreed rent is strong evidence.
3. A letting agent's written opinion. Ask for the comparables behind it, not just a figure.
4. Condition evidence. Dated photos, recent safety certificates, and invoices for repairs or upgrades.
5. Your tenancy terms. What's included in the rent: furniture, bills, parking, garden.

Keep your evidence honest. If a comparable is better than your property, say so and adjust. Evidence that deals openly with the differences is easier to rely on.

Adjusting comparables for differences

Rarely is a comparable identical. Note each difference and which way it pushes the rent.

Difference	Usually pushes your figure
Comparable has an extra bedroom or more floor space	Down
Comparable has been recently refurbished; yours hasn't	Down
Your property includes bills (for example broadband) and the comparable doesn't	Up, by roughly the value of the bills
Your property has parking or a garden; the comparable doesn't	Up
Comparable is in a different street or area with different demand	Either; explain why it's still relevant
Comparable is furnished; yours is unfurnished	Down

Don't put a precise value on each adjustment unless you can support it. A short, reasoned explanation is better than false precision.

How the rental bidding ban changes advertised rents

Since 1 May 2026, every written advert or offer for a let must state one specific rent. "A price range is not allowed." After advertising, a landlord or agent must not ask for or accept offers above the advertised rent, or encourage bidding.

That has two effects on your evidence:

• Advertised rents are clearer. You won't see "offers over" or a range. Each advert gives one figure.
• An advert's figure is a ceiling for that letting. The landlord can't accept more than the advertised rent.

So asking rents are useful, but note whether a property stayed on the market for weeks, which can suggest the rent was too high. Read more about the rental bidding ban.

A comparables log you can copy

Keep a simple log like this for every rent increase. It takes minutes and it's exactly what you need if the tenant goes to the tribunal.

Property: [your property address]
Current rent: £[amount] per [month/week]   Proposed rent: £[amount] per [month/week]
Terms: [furnished/unfurnished], bills included: [none / list]

| # | Address or area | Type and size | Condition | Furnished? | Bills incl.? | Rent | Source and date seen | Difference from mine |
|---|-----------------|---------------|-----------|------------|--------------|------|----------------------|----------------------|
| 1 | [street, town]  | [2-bed flat]  | [good]    | [no]       | [no]         | £[ ] | [site/agent, date]   | [e.g. has parking]   |
| 2 |                 |               |           |            |              |      |                      |                      |
| 3 |                 |               |           |            |              |      |                      |                      |

Condition of my property on [date]: [summary; photos saved as ...]
My reasoning: [two or three sentences linking the comparables to the proposed rent]

Using your evidence if the tenant goes to tribunal

If the tenant applies on form MR1, they should tell you, and you can reply. Send a concise summary with your log, copies of the adverts or valuations, and photos of the property's condition. Keep everything dated. Our guide to tenant challenges at tribunal explains what the tribunal decides and when the new rent starts.

Remember the cap works one way. If the tribunal finds the market rent is higher than your proposal, you still get only your proposed rent. If it finds it's lower, the rent is cut to the market level. See how much a landlord can increase rent.

What to do next

• When your figure is ready, create Form 4A free with a ValidNotice account from the Section 13 notice page.
• Summarise your evidence for the tenant in a rent increase letter sent with the form.