Rent increases explained: section 13, Form 4A and the tribunal

Rent increases are now one of the most tightly timed parts of a tenancy in England. There is exactly one lawful route to a higher rent, one prescribed form, a minimum notice period, a limit of one increase a year, and a rule about which day the new rent can start on. Miss any of them and the notice does not work. This guide sets out the route, the timing rules that decide whether a notice is valid, a worked example with real dates, and what happens when a tenant asks the First-tier Tribunal to look at the figure.

The only lawful route: a section 13 notice

A landlord who wants to raise the rent has to serve a notice under section 13 of the Housing Act 1988, using the prescribed Form 4A. That is the whole mechanism. A letter, an email, a text message or a clause in the tenancy agreement will not do the job, however clearly it is worded and however reasonable the proposed figure is.

The form does something useful for both sides. It states the current rent, the proposed rent and the date the new rent is meant to begin, and it tells the tenant that they can challenge the figure. That means a tenant who receives one is not guessing at their options, and a landlord who serves one has a dated document to rely on later.

The four timing rules

All four apply at once. A notice can give six months' warning and still fail because the effective date falls in the middle of a rent period, or because it is 11 months since the last increase rather than 12. The rent increase checker tests a set of dates against all four at once.

A worked example

Take a tenancy that began on 1 September 2026, with rent of £1,150 per calendar month payable on the 1st. The landlord wants to raise it to £1,225 as soon as the law allows.

The 52-week rule bites first. Fifty-two weeks from 1 September 2026 ends on 31 August 2027, so no increase can take effect before that. The effective date also has to be the first day of a rent period, and in this tenancy rent periods run from the 1st of each month. The earliest workable effective date is therefore 1 September 2027.

Working backwards, 2 months' notice means the Form 4A has to reach the tenant on or before 1 July 2027. Serve it on 15 July and the notice cannot take effect until 1 October 2027 instead - the increase is not lost, it is simply pushed back a month. And once the new rent starts on 1 September 2027, the next increase cannot take effect before 1 September 2028.

What "the first day of a rent period" means

A rent period is the recurring block the rent is charged for. In a monthly tenancy where rent falls due on the 8th, the rent periods run from the 8th of one month to the 7th of the next, so an increase can only start on the 8th. In a weekly tenancy it can only start on the same weekday the rent falls due. This is a common way for otherwise sensible notices to fail, particularly where a landlord picks the 1st of a month out of habit. The guide to periodic tenancies explains how rent periods are set.

Rent review clauses no longer have effect

Many older agreements contain a clause saying the rent rises annually, or rises in line with an index, or rises by a fixed percentage on the anniversary. Those clauses no longer have effect in an assured tenancy. Whatever the agreement says, the increase has to be proposed on a Form 4A and has to satisfy the four timing rules.

This matters for landlords who have set up standing orders or accounting on the assumption that a contractual uplift will happen automatically. It will not, and money collected above the lawful rent is not simply an administrative error to be tidied up later. If you are drafting a new agreement, the rent increase position is one of the matters that has to be set out in the written statement of terms.

Challenging the rent at the First-tier Tribunal

A tenant who thinks the proposed rent is above the market can refer it to the First-tier Tribunal. The application has to be made before the date the increase is due to take effect, which is the single most important thing for a tenant to know - the two months between the notice and the effective date is the window, and it does not reopen.

The tribunal decides what an open market rent for the property would be, based on comparable local lettings rather than on what either party can afford. Two limits shape the outcome. It cannot set the rent higher than the figure the landlord proposed on the notice, so a tenant who challenges cannot end up worse off than the notice would have left them. And it cannot backdate an increase: the rent it determines applies from the date of its determination, not from the date on the landlord's notice.

For landlords, that combination is a reason to propose a defensible figure supported by comparable properties rather than an opening bid. For tenants, it means a challenge is worth considering on its merits rather than avoided out of fear of a worse result. Your wider position is covered in tenant rights under the Act.

Rent in advance and money at the start

Separate rules govern what can be asked for up front. A landlord can require no more than one month's rent in advance, or 28 days' rent where the rental period is shorter than a month, and no rent can be taken before the tenancy agreement is signed (a holding deposit of up to one week's rent is still allowed). That closes off the practice of using large advance payments to filter applicants. The related rules on rental bidding and discrimination are in discrimination, bidding and rent in advance, and the full sequence of landlord duties and dates is in the compliance timeline.