Rent increase calculator

How rent increases work now

Since the Renters’ Rights Act took effect on 1 May 2026, the rent on an assured tenancy in England, which includes every former assured shorthold, can only be put up with a section 13 notice. The notice is Form 4A, “Landlord’s notice proposing a new rent”. A rent review clause in the tenancy agreement no longer works, and you still need the form when your tenant has already agreed the new figure.

This guide covers England. Wales, Scotland and Northern Ireland have their own rules, so check the requirements for where your property is.

When the new rent can start

The calculator applies four rules and gives you the latest of the dates they produce.

• At least two months between serving the notice and the new rent starting
• No increase in the first 52 weeks of the tenancy
• No increase within 52 weeks of the last one, whether that was by section 13, by a tribunal, or by a rent review clause used before 1 May 2026
• The new rent starts on the first day of a rental period, so on a rent day

Serving the notice

You can hand the notice to your tenant, post it, or email it if the tenancy agreement allows notices by email. If you post it, allow for delivery: the calculator treats first class post as arriving on the second working day after posting, which can push the start back by a whole month if it misses a rent day. Keep a copy and a record of how and when you served it.

Setting the new rent

The new rent should be in line with what the property would let for on the open market. Your tenant can refer the notice to the First-tier Tribunal (Property Chamber) before the new rent is due to start. The tribunal decides the market rent and cannot set it higher than the rent in your notice. If the tenant refers it, the new rent starts from the date the tribunal decides rather than the date in your notice.

Add the market rent of similar homes nearby to the calculator to see how your proposal compares. An increase at or below the market rent is far less likely to be challenged, and a rent well below market is income you are leaving on the table each year.

Keeping track of rent reviews

The awkward part is not the sum but remembering the date. TenantTool records each tenancy’s rent, its next review date and the letters behind it, and puts the review on your calendar, so a rent increase is never missed for another year.