Section 13 rent increase date calculator

This Section 13 date calculator finds the earliest date a new rent can start on Form 4A, the notice private landlords in England must use to increase rent since 1 May 2026. Enter the date the tenant receives the notice, when the tenancy began, the date of any previous increase and how often rent is due. The result is the date to put in question 4.6.

How to use the Section 13 date calculator

1. Date the tenant receives Form 4A. Count from when the tenant actually gets it. If you post it, allow extra days, or hand-deliver it.
2. Tenancy start date. Enter the first day of the first rent period. The calculator uses it for the 52-week rule and to find your rent days.
3. Date the last rent increase took effect. Leave it blank if the rent has never gone up during this tenancy.
4. How often rent is due: monthly, weekly, fortnightly or every four weeks.

The result shows the earliest start date, the date each rule produces, and notes on anything that moved the date.

The rules the calculator applies

The start date in question 4.6 must meet all three rules in the Housing Act 1988 section 13 and Form 4A's notes. The calculator takes the latest date the rules allow:

1. At least 2 months after service. Months are counted to the same day number; where that day doesn't exist (for example 31 December plus 2 months), we use the 1st of the following month, the conservative choice.
2. At least 52 weeks after the tenancy began, and after the last increase took effect. The calculator adds 364 days to each date.
3. The first day of a rent period. For monthly rent, that's the same day of the month the tenancy began. For weekly, fortnightly and four-weekly rent, periods are counted in 7, 14 or 28-day blocks from the start date, so a weekly tenancy that began on a Monday gets a Monday.

Two cautions:

• The 53-week rule. If 52 weeks after the last increase would fall more than 6 days before the anniversary of the first increase, you must wait 53 weeks instead. The calculator reminds you of this when you enter a last increase date, but doesn't work it out. Check it if your rent day has drifted.
• Month-end rent days. If your tenancy began on the 29th, 30th or 31st, in shorter months the calculator uses the last day of that month. Check this matches your tenancy's rent day.

Worked examples

Tenancy began	Rent	Last increase	Form 4A received	Earliest new rent	Why
20 March 2024	Monthly	None	Monday 2 November 2026	Wednesday 20 January 2027	2 months gives 2 January; the next rent day is the 20th
1 June 2026	Monthly	None	Monday 2 November 2026	Tuesday 1 June 2027	No increase in the first 52 weeks (31 May 2027), then the next rent day
Monday 6 January 2025	Weekly	None	Thursday 5 November 2026	Monday 11 January 2027	2 months gives 5 January; the next rent week starts on a Monday
10 May 2023	Monthly	10 April 2026 (rent review clause)	Monday 2 November 2026	Saturday 10 April 2027	52 weeks after the April increase is 9 April 2027, so the next rent day

Watch out: In the second example, serving the notice early doesn't help: GOV.UK is clear that you can't increase the rent in the first year of the tenancy.

What the calculator doesn't check

• The new amount. It doesn't tell you what rent to propose. See how much a landlord can increase rent.
• The form. You must use Form 4A, unchanged. Using old Form 4, a letter or an email is a common reason increases fail; see invalid rent increase mistakes.
• Service. You need to be able to prove when the tenant received the notice and that every joint tenant was named.
• The 53-week rule, as above.

It covers private assured periodic tenancies in England only. Social landlords use Form 4, and Wales has different law. Rent periods longer than a month are no longer allowed.

What to do next

Create your Form 4A with ValidNotice, using the same date rules. If your tenant may push back, read how a tenant can challenge a rent increase at the tribunal. All our free tools are on the landlord calculators page.