Form 4A: the prescribed form for a rent increase

Last updated August 2026

What Form 4A is

Form 4A is the prescribed government form titled "Landlord's notice proposing a new rent for an assured tenancy in the private rented sector." It's the document that carries a Section 13 rent increase. Using the right, current version is not optional - an out-of-date form or a homemade letter makes the increase invalid.

Form 4A is not the same as Form 4. Since 1 May 2026, Form 4A is the form for private rented assured tenancies, while the old Form 4 is now used for social housing only. If you're a private landlord, Form 4A is the one you need.

What information it asks for

• The address of the property the tenancy relates to.
• The landlord's name and contact address (the address the tenant can serve documents to).
• The tenant's name(s).
• The current rent and the proposed new rent, and how often it's paid.
• The date the new rent will start.
• Whether the rent has been increased before, to apply the once-a-year rule correctly.

The form also includes the statutory notes that tell the tenant about their right to challenge the rent at the tribunal - these must be present, which is one reason a custom letter won't do.

The dates that void the notice

Most invalid Form 4A notices fail on dates, not content:

• The new rent must start at least two months after service.
• It must fall at the start of a tenancy period (for a monthly tenancy, your usual rent day).
• It must be at least 52 weeks after the last increase (or the start of the tenancy).

See what makes a notice invalid for the full list.

The easy way to get it right

You can download a blank Form 4A from GOV.UK and complete it by hand. The risk is the dates and the once-a-year rule. Our generator produces a completed, current Form 4A with the effective date already calculated and checked - ready to download and serve.