National Rent Cap Ireland 2026: How Much Can You Legally Increase Rent?

If you last checked the rules before 2026, the ground has moved. The Rent Pressure Zone system — where the cap only applied in designated areas — is gone. In its place is one national rent control regime under the Residential Tenancies Acts, and it covers the whole country.

That's good news in one sense: there's now a single set of rules to learn. But it also means many landlords who assumed they were exempt, because their property sat outside an RPZ, are now fully inside the regime. Get a rent review wrong today and the increase is invalid, the tenant can dispute it, and you can be ordered to repay. Let's make sure that doesn't happen.

What changed on 1 March 2026

The single most important thing to understand about 2026 is this: Rent Pressure Zones no longer exist as a separate category. The Irish government replaced RPZ designations with a national rent control system under the Residential Tenancies Acts. The cap — the lower of 2% per year or the HICP rate — now applies to every private residential tenancy, not just to properties in previously designated areas.

In practice:

• There is no longer a distinction between "RPZ" and "non-RPZ" properties.
• The same rent review rules apply whether the property is in Dublin 4 or rural Leitrim.
• Landlords who assumed they were exempt because they were outside an RPZ are now fully subject to the cap.
• Exceeding the cap is a serious breach — it can lead to RTB proceedings and damages against the landlord.

"HICP" is the Harmonised Index of Consumer Prices — the inflation measure the RTB publishes for use in the rent cap. Where you calculate against inflation, it's the HICP figure that matters, not a general "cost of living" number you read in the news.

The 3 rules every valid rent increase must satisfy

A rent increase in Ireland is only valid if it meets all three of these conditions at once. Miss any one, and the increase is legally unenforceable.

Rule 1 — Wait 12 months

You can review the rent no more than once every 12 months, measured from when the rent was last set — not from the tenancy start date, and not from the calendar year. If you set a new rent on 15 June 2025, the earliest you can review it again is 15 June 2026. A common, costly mistake is counting from the original lease date rather than the date the rent was actually last changed. Always trace the rent history.

Rule 2 — Respect the cap: the lower of 2% or HICP

The maximum increase is the lower of these two figures:

• 2% annual cap — 2% per year, pro-rated for the actual number of months since the rent was last set.
• HICP cap — the percentage change in the RTB-published HICP since the rent was last set.

Whichever number is lower is the most you can legally charge. When inflation is low, the HICP figure can come in under 2% and becomes the binding limit; when inflation is higher, the 2% ceiling wins.

Rule 3 — Give 90 days' written notice

You cannot simply start charging more from a chosen date. You must serve a formal, written Rent Review Notice stating the new rent and the effective date, which must be at least 90 days after the tenant receives it. The clock starts on receipt, not on posting — so if you send by post, allow extra days for delivery. Less than 90 days and the notice is invalid, full stop.

Worked example: how the cap is calculated

Say the rent was last set 18 months ago. You need to compare the pro-rated 2% cap with the HICP figure for that period, and take the lower:

The figures above are illustrative — the actual HICP rate changes over time, so you must use the current RTB-published figure for your own review. That's exactly the lookup that trips people up: use last year's number, or a general inflation figure from the news, and the calculation is wrong before you start.

Serving a valid Rent Review Notice, step by step

1. Confirm 12 months have passed since the rent was last set. If in doubt, trace the rent history rather than the lease date.
2. Calculate the permitted increase — pro-rate 2% over the months elapsed, compare with the current HICP figure, and take the lower.
3. Draft the written notice stating the new rent and the effective date (at least 90 days from receipt). Email is acceptable only where the tenant has agreed to electronic communication in writing.
4. Serve it and keep proof. Retain a copy — if a dispute arises years later, you'll need to show the notice was served correctly.
5. Record the next eligible review date — 12 months from the effective date — so the next review isn't served too early.

What happens if the tenant disputes the increase

A tenant who believes an increase exceeds the cap can refer the matter to the RTB within 28 days of the date the new rent takes effect — not from when they received the notice. If the RTB finds in the tenant's favour:

• The excess amount must be repaid to the tenant.
• Damages of up to €20,000 can be awarded against the landlord.
• The RTB can order that the lawful rent figure applies instead.

This is why the calculation has to be right. A notice built on the correct 12-month date, the correct HICP figure and a full 90 days is a notice that holds up.

When the national rent cap doesn't apply

The rules don't cover every arrangement. The main exceptions include:

There's also a separate question around new tenancies: whether you can reset to market rent when you re-let depends on why the previous tenancy ended. If you ended it on a no-fault basis — selling, a family member moving in, or substantial refurbishment — the previous rent cap generally continues to apply to the new tenancy. If you're unsure, get advice before setting the new rent.

How TenantSync checks every rent review automatically

The mechanics above are simple to describe and easy to get wrong at scale — especially across a portfolio where every tenancy has a different "last set" date and its own next-eligible-review date. That's the job TenantSync does for you.

• National Rent Cap calculator — computes the maximum allowable rent for a tenancy in about 30 seconds, applying the lower of the 2% and RTB-published HICP figures.
• Compliant notice, generated for you — the rent review notice is produced with the new rent and effective date, ready to serve.
• Every date tracked — the 12-month clock, the 90-day notice window and the next eligible review date are held per tenancy, so nothing is served too early.
• One platform — rent reviews sit alongside your RTB registration tracking, PSRA obligations and Open Banking rent reconciliation, on web, iOS and Android.

Frequently asked questions