What to do when the rent goes up by more than it should
Check the amount, the interval and the notice, in that order. Then the Residential Tenancies Board dispute route, and what it can and cannot get back.
Three separate things can be wrong with a rent increase, and they are worth checking in order because the easiest to prove is not the amount. Most invalid increases fail on timing or on the notice long before anybody gets to the arithmetic.
First, the interval
Rent may only be reviewed once in any twelve month period. If the last increase was less than a year ago, the new one is invalid regardless of its size, and this is the single most common defect. Find the date of the last change before you look at anything else.
Second, the notice
- It must be in writing and must state the new rent and the date it takes effect.
- It must give at least 90 days before the new rent starts.
- It must set out how the new rent was arrived at, which since national rent control means showing the calculation rather than asserting a figure.
Third, the amount
Under national rent control an increase is capped by inflation, and the cap is applied to the rent as it stands rather than to some earlier figure. Whether a property is exempt is a separate question with its own conditions, and an exemption claimed but not established is not an exemption.
Raising it with the landlord
In writing, quoting the specific defect: the date of the previous review, the number of days in the notice, or the calculation. A landlord who has made an honest mistake usually corrects it at this point, and many increases that look deliberate are somebody applying last year's rules.
If that does not resolve it
- A dispute application to the Residential Tenancies Board. Mediation or adjudication, with a fee, and no solicitor needed.
- There is a time limit. A dispute about the validity of a rent review has to be brought within 28 days of receiving the notice, which is short enough that waiting to see what happens can cost you the route.
- Keep paying the existing rent in the meantime. Withholding it turns your complaint into arrears and hands the other side a termination ground.
Where an overpayment has already been made, the Board can order it repaid. That is a reason to raise it early rather than to let it run and hope, because the amount at stake grows and the 28 day window does not.
Sources
- Maximum annual rent increase, Residential Tenancies Board
- Minimum months between rent reviews, Residential Tenancies Board
Questions people ask
- How do I know if a rent increase is legal?
- Check three things in order: whether a year has passed since the last review, whether the notice gave at least 90 days and showed how the figure was reached, and only then the amount itself. Most invalid increases fail on one of the first two.
- How often can rent be increased?
- Once in any twelve month period. If the last increase was less than a year ago the new one is invalid whatever its size, and this is the single most common defect.
- What notice is required for a rent increase?
- At least 90 days in writing, stating the new rent, the date it takes effect, and how it was arrived at. Asserting a figure without showing the calculation is not enough.
- How long do I have to dispute a rent increase?
- A dispute about the validity of a rent review has to be brought within 28 days of receiving the notice. That is short enough that waiting to see what happens can cost you the route entirely.
- Can I get an overpayment back?
- Where rent above the lawful amount has already been paid, the Residential Tenancies Board can order it repaid. That is a reason to raise it early, because the amount grows while the 28 day window does not.
- Should I stop paying rent while I dispute it?
- No. Keep paying the existing rent. Withholding it turns your complaint into arrears and hands the other side a ground for terminating the tenancy.
Figures checked 8 August 2026.