Section 13 rent increase calculator
Works out the earliest date a rent increase can start under a Section 13 notice (Form 4A). England. Free, no sign-up.
Advanced options
The rules
A landlord raises the rent of an assured periodic tenancy in England by serving Form 4A. GOV.UK says the notice must give at least 2 months, and the new rent must start at the beginning of a rent period. The tenant can ask the First-tier Tribunal to decide the market rent before the start date.
The increase cannot take effect sooner than 52 weeks after the tenancy began (for the first increase) or after the last increase. In some cases the gap is 53 weeks: where the 53rd week after the last increase starts more than 6 days before the anniversary of the first increase since 11 February 2003. The calculator applies that rule when you give it the dates.
How the calculator works
- It adds 2 months to the date you serve the notice.
- It adds 52 weeks (or 53 where required) to the tenancy start or last increase.
- It takes the later of the two, then moves forward to the next day a rent period begins.
Rent periods are taken from the tenancy start date, or from the date you enter under advanced options. If your rent day differs from your tenancy start day, enter a date a rent period begins.
Limits
This tool assumes an assured periodic tenancy where the rent is varied by a Section 13 notice and no valid rent review clause is used. It does not check the amount of the new rent. If your tenancy agreement has a different agreed method, take advice.
Who this calculator is for
Landlords and tenants in England with an assured periodic tenancy, where the rent is increased by a Section 13 notice on Form 4A. It tells you the earliest date the new rent can start, so you can check a notice before it is served or check one you have received.
How to use it
- Enter the tenancy start date and the date you will serve Form 4A.
- If the rent has increased before, enter the date of the last increase.
- Choose how often rent is paid.
- Use the advanced options only if your rent day is different from the tenancy start day, or you know the date of the first increase since 11 February 2003.
Worked examples
- Tenancy starts 1 June 2026, rent paid monthly, notice served 1 December 2026: the earliest start is 1 June 2027. The 52 weeks end on 31 May 2027, so the new rent starts at the next rent period.
- Same tenancy, notice served 15 June 2026: again 1 June 2027, because the 52 week gap is the limit, not the notice period.
- Last increase 1 September 2026, notice served 1 May 2027: the earliest start is 1 September 2027.
If the tenant disagrees
A tenant who thinks the proposed rent is above the market rent can refer the notice to the First-tier Tribunal before the new rent starts. This calculator does not assess the amount of the rent.
Common mistakes
- Serving a notice that gives less than two months.
- Choosing a start date in the middle of a rent period.
- Increasing again before 52 weeks have passed since the last increase.
What changed under the Renters' Rights Act 2025
The GOV.UK guide to the Renters' Rights Act says rent can go up only once a year, by a Section 13 notice, with at least two months' notice. Rent review clauses in tenancy agreements are not permitted, so a Form 4A notice is the usual route. A tenant can challenge the proposed rent at the First-tier Tribunal.
If you are the tenant
You have the right to ask the First-tier Tribunal to decide the market rent before the new rent starts. You do not have to agree to the new figure. Use this calculator to check the notice gives you enough time and that the start date is not earlier than the law allows.
- Look at the date on Form 4A and the start date for the new rent.
- Compare the proposed rent with similar properties locally.
- Apply to the tribunal before the start date if you want it checked. GOV.UK explains how.
Choosing the right start date
If rent is paid monthly on the 1st, the new rent has to start on a 1st. Weekly rent starts on the same weekday each week, so a weekly tenancy can often start the increase sooner than a monthly one. Entering your actual rent day under advanced options avoids a date that falls in the middle of a period.
Common questions
- How much notice does a Section 13 rent increase need?
- GOV.UK and Form 4A say at least two months. The calculator adds two months to the date you serve the notice.
- Why is my date later than two months after service?
- Either 52 weeks have not yet passed since the tenancy began or the last increase, or the new rent has to start at the beginning of a rent period.
- Can the rent go up twice in a year?
- No. At least 52 weeks must pass between increases, and in some cases 53 weeks.
- What is the 53 week rule?
- It applies where the 53rd week after the last increase begins more than 6 days before the anniversary of the first increase since 11 February 2003. Use the advanced option to enter that date.
- Can a tenant challenge the new rent?
- Yes. The tenant can refer the notice to the First-tier Tribunal before the new rent starts.
- What is Form 4A?
- It is the prescribed form a landlord uses to propose a new rent under Section 13 of the Housing Act 1988. GOV.UK publishes it.
- Can a landlord use a rent review clause instead?
- The GOV.UK guide to the Act says rent review clauses are not permitted, so Section 13 is the route.
- Does the 52 weeks count from the tenancy start or the last increase?
- From the tenancy start for the first increase, and from the date of the last increase for later ones, with the 53 week variation in some cases.
- Does this tell me if the new rent is fair?
- No. It only works out dates. The tribunal decides market rent.
Related guides
Other free tools
- Section 8 notice dates: Earliest date to put on a Section 8 notice.
- Deposit deadline: When a deposit must be protected, and when to return it.
- Deposit cap: Maximum deposit and holding deposit for a given rent.
- Tenancy timeline: Key dates from the start of a new tenancy.
Sources
- Housing Act 1988, section 13
- GOV.UK: rent increases for assured tenancies
- Form 4A (GOV.UK)
- GOV.UK guide to the Renters' Rights Act
Last checked 29 October 2026. Found a mistake? Tell us.