A planning tool, not legal advice. It works out the key dates for a section 13 notice. It does not tell you what rent to ask for, and it does not replace checking the notice itself before you serve it.
The short version
Since 1 May 2026 there is only one lawful way to raise the rent on an assured tenancy: a section 13 notice. Rent review clauses in the agreement do nothing. You can increase the rent once every 12 months, you must give at least two months’ notice, the new rent must start at the beginning of a rent period, and the tenant can challenge it at the First-tier Tribunal — which can set the rent at the market level, and cannot set it higher than you asked for.
The calculator
The rules the calculator applies
| Rule | Detail |
|---|---|
| Once a year | No more than one increase in any 12-month period. The clock runs from the last increase, or from the start of the tenancy if there has not been one. |
| Two months’ notice | Minimum. Longer is fine and often lands better. |
| Start of a rent period | The new rent must take effect at the beginning of a period, not part way through a month. |
| Prescribed form | A section 13 notice must be in the correct form. A letter is not a section 13 notice. |
| Tribunal challenge | The tenant may apply before the new rent starts. The tribunal decides the open market rent and cannot set it above what you proposed. |
| Rent review clauses | Have no effect. Section 13 is the only route. |
Ask for a defensible number. Because the tribunal can only set the rent at market level or lower, an ambitious increase carries a specific risk: the tenant challenges, the tribunal decides the market rent is below your figure, and you end up with less than you would have got by asking sensibly. Evidence your figure with comparable local listings before you serve.
Read next
How often can I raise the rent?
Once in any 12-month period, using a section 13 notice.
How much notice do I have to give?
At least two months, and the new rent must begin at the start of a rent period.
Can I use the rent review clause in my agreement?
No. Rent review and automatic uplift clauses have no effect on an assured tenancy. Section 13 is the only lawful route.
Can the tenant refuse?
They cannot simply refuse, but they can apply to the First-tier Tribunal before the new rent starts. The tribunal sets the open market rent and cannot set it higher than you proposed.
What if the tenant just keeps paying the old amount?
If the notice was valid the new rent is legally due, and the shortfall is arrears. Raise it in writing promptly rather than letting it accumulate.
Can I increase the rent in the first year?
Not within 12 months of the tenancy starting. The first increase can take effect once that period has passed, with the notice served at least two months before.
Sources. Housing Act 1988, section 13, as amended by the Renters’ Rights Act 2025 (c. 26); Renters’ Rights Act 2025 (Commencement No. 2) Regulations 2026 (SI 2026/421); First-tier Tribunal (Property Chamber) guidance on rent determinations. Checked 8 September 2026.
Related: The Renters’ Rights Act · All calculators · All guides