Is Your Rent Increase Invalid?

Since 1 March 2026, a new national system of rent control applies to every private tenancy in Ireland — replacing the old Rent Pressure Zone (RPZ) system under the Residential Tenancies (Miscellaneous Provisions) Act 2026. That means almost every rent increase is capped, and a great many of the increases landlords serve are, in fact, invalid. If yours breaks the rules, you do not have to pay it. This guide explains exactly when a rent increase is unlawful and how to push back.

Key Points

• National rent control applies to every tenancy — new and existing
• Rent can rise by no more than the lower of inflation (CPI) or 2% per year
• Rent can only be reviewed once every 12 months
• You must get at least 90 days' proper written notice
• Since March 2026, your landlord must also copy the notice to the RTB within 7 days
• Break any one of these and the increase is invalid — you can dispute it

The Five Tests for a Valid Rent Increase

1. The amount — the 2% cap

Rent cannot rise by more than the lower of general inflation or 2% per year, under the Residential Tenancies Act 2004 as amended by the Residential Tenancies (Miscellaneous Provisions) Act 2026. Since 1 March 2026, inflation is measured by the Consumer Price Index (CPI), replacing the older HICP measure. A jump from €1,500 to €1,800 — a 20% rise — is a textbook invalid increase.

2. The frequency — once every 12 months

Rent can be reviewed no more than once in any 12-month period, and not within the first 12 months of the tenancy. A second increase inside a year is invalid.

3. The notice — 90 days, in the right form

You must receive at least 90 days' written notice in the prescribed form, stating the current rent, the new rent, and the date the new rent takes effect. A verbal increase, a text message, or short notice does not count.

4. The evidence — comparable rents

The landlord must also provide details of three comparable rents for similar dwellings in the area (drawn from the RTB Rent Register). If they did not, the notice is defective.

5. The RTB copy — sent within 7 days (new from March 2026)

Since 1 March 2026, your landlord must send a copy of the rent review notice to the RTB within 7 days of the date it is sent to you (the same day, before 14 September 2026). If they only tell you and never notify the RTB, the notice can be treated as invalid — this is a new, easy-to-miss requirement worth checking specifically.

How to Dispute It

The effective first step is a clear, written letter to your landlord that names the specific rule being breached and states that you will refer the matter to the RTB if it is not withdrawn. A referenced letter reads very differently from a complaint — many landlords back down once they see you know the law. If it isn't resolved, you can apply to the RTB for dispute resolution (check rtb.ie for current fees).

Frequently Asked Questions

Related Guides

See also: getting a deposit back when a landlord won't return it, challenging an invalid eviction notice, and how to write an RTB dispute letter.