The RTB's September update: what it means if you're letting

The figures, and what each one is

The release publishes administrative data and rent figures together, but they are not the same period. Read each line below with its own quarter and its own series.

The number to hold next to a vacancy

The €326 gap is the figure to read against the rent-setting rules. When a tenancy turns over for a permitted reason, the rent on the new letting can be set at the market rate, and that is why the two registered figures sit so far apart. While a tenancy continues, a review increase is capped at the lower of the statutory ceiling and CPI, so the market rate is not the number that governs it.

The practical version: know which side of the gap your next letting falls on, and work out the numbers before you advertise. Our rent-increase guide sets out when a reset is available and when the cap applies.

Half of the termination notices are landlords selling

Of the 4,031 notices received in Q2 2026, 2,023, just over half, stated an intention to sell. A notice on the ground of sale is a no-fault termination, so the longer notice periods apply, the copy still has to reach the RTB within 7 days, and the rent cannot be reset to the market rate when the property is relet. The notice-periods guide covers the process for each ground, step by step.

Compliance: what the release shows

The same release covers the RTB's enforcement work: 10 new sanctions against landlords totalling €57,080, and 1,133 compliance notices in Q2 2026 for failure to register a tenancy. From 14 September 2026, fixed payment notice powers are also available, with the first campaigns targeting rent-setting and registration non-compliance.

• Registration: keep every tenancy registered and renewed. The RTB registration guide walks through it.
• Rent setting: a rent review needs the tenant served, the copy with the RTB within 7 days, at least 90 days' lead, and the calculator printout with comparables. The rent-increase guide has the full pack.

The 14 September package is the detail behind that second campaign. We have walked through what changed, and what to do about it, in our September rental-rule changes checklist.

Cost rental and AHB growth, as context

Two register lines are context rather than competition for a private landlord: cost rental at 6,186 tenancies (+82.5% year on year) and approved housing body tenancies at 59,055 (+11.5%). Both are reported alongside the private register count, and both sit outside the private rent framework.

The caveat that comes with the rent index

The release carries the ESRI's own reading of the rent index: it is too early to tell how much of the rise in new-tenant rents is adjustment to the March 2026 reset rules rather than a sustained shift. We have kept that sentence in because it applies to the rent figures above, including the €326 gap.

If you are letting this month

The update points to two checks a landlord can act on: the rent, and the tenant. If a tenancy is turning over, our affordability calculator shows what a household needs to earn to carry a rent like the €1,839 new-tenancy average.

If a tenancy is continuing, the rent-increase guide covers what a review can add, and the Part 4 tenancy guide covers what the six-year cycle means for when you can end one.

Common questions

Is the €1,839 figure an asking rent?

No. It is the registered rent on new tenancies in Q1 2026, from the RTB/ESRI Rent Index: rents actually agreed and registered. Asking rents are what new listings advertise, and they are reported separately.

What are the RTB's fixed payment notices?

From 14 September 2026 the RTB can issue fixed payment notices for six breaches, with a 28-day payment window and a figure of €200 for a rent breach and €100 for the others. The initial campaigns target rent-setting and registration non-compliance.

Did the rent cap change in this update?

No. The update reports on the sector; it does not change the rules. A review increase is still capped at the lower of the statutory ceiling and CPI, and whether the rent can be reset to the market rate still depends on how the tenancy ends.

Sources

Every figure and date here is sourced and dated, and restated in our own words.

• RTB, Director's quarterly update on the rental sector, September 2026
• RTB/ESRI Rent Index (registered rents, new vs existing)
• RTB, setting and reviewing private rents from 1 March 2026

Figures from the RTB Director's update of 3 September 2026, checked against the release on 20 September 2026.