Rent Increase Rules 2026: Check the Legal Cap

Leinster house prices & rents › Rent increase rules

Since 1 March 2026 every tenancy in Ireland is under the same rent rules: an increase is capped at the lesser of 2% a year (pro rata) or CPI inflation over the period since the rent was last set. The old Rent Pressure Zone boundaries are gone; the cap is national and permanent. Updated July 2026.

Check a rent increase against the cap

The calculator applies the statutory formula (Residential Tenancies Act 2004 s.19(4), as amended in 2026) using the CSO All Items Consumer Price Index, the index the Act names. Pick your town to see the local average rent alongside.

The rules a valid rent review must follow

90 days' written notice on the RTB's Notice of Rent Review form, and a copy to the RTB the same day it goes to the tenant.
No more than one review in any 12 months.
Three comparable homes cited from the RTB Rent Register by their RT numbers: similar size, bedrooms, type and BER, in a comparable area.
The dwelling's floor area and BER stated on the notice.
Inside the cap. Setting a rent above it, or outside these rules, is improper conduct the RTB can sanction (up to €15,000 per breach), and for notices served since March 2026, a criminal offence.

If the notice you received is over the cap

You can dispute a rent review with the RTB, and an invalid notice does not take effect. Check the figure with the calculator above, keep the notice, and use the RTB's own rent calculator printout as your evidence. New tenancies may lawfully be set to market rent in limited cases, such as after a tenant chooses to leave, or after a compliant six-year cycle, so a higher advertised rent on a new letting is not automatically a breach.

Sources: Residential Tenancies Act 2004 as amended to 2026; CSO All Items CPI (PxStat CPM02, CC BY); RTB average rents via CSO (RIQ02, CC BY). General guidance, not legal advice.