March 2026 Rental Law Changes: What Landlords Need to Know

March 2026 brought the most significant overhaul of Irish residential tenancy law in over a decade. The Residential Tenancies (Amendment) Act introduced sweeping reforms that affect every landlord and tenant in the country. Whether you own a single investment property or manage a portfolio, you need to understand these changes to remain compliant and avoid costly disputes at the RTB.

This guide covers the five major areas of reform: the introduction of national rent control, the replacement of Part 4 tenancies with Tenancies of Unlimited Duration (TMD), new landlord size classifications, exemptions for new construction, and the transitional rules for existing tenancies.

National Rent Control Replaces RPZs

The old Rent Pressure Zone (RPZ) system, which applied only to designated areas, has been replaced with a nationwide rent control regime. Every residential tenancy in Ireland is now subject to the same rent increase cap, regardless of location. The cap ties allowable increases to the Harmonised Index of Consumer Prices (HICP) published by the CSO, with a hard ceiling of 2% per year even if inflation runs higher.

In practical terms, this means that landlords in areas that were previously outside RPZs can no longer set rent increases based on open market comparisons alone. Every rent review must comply with the HICP-linked formula, and the minimum interval between reviews remains 12 months. Landlords must still provide at least 90 days' written notice before any increase takes effect.

The transition from RPZs was immediate. From the commencement date, all existing RPZ designations ceased to have effect, and the national formula applies instead. If you had a rent review pending under the old RPZ rules, the new rules apply unless the notice was already validly served before the commencement date.

TMD Replaces Part 4 Tenancies

Part 4 of the Residential Tenancies Act previously granted tenants security of tenure in rolling 6-year cycles. After an initial 6-month probationary period, a tenant acquired Part 4 rights for the remainder of a 6-year period, with further rights available upon entering subsequent cycles.

Under the new regime, Part 4 is replaced by Tenancies of Unlimited Duration (TMD). The fundamental shift is that once a tenant has been in occupation for six months, their tenancy becomes a TMD — a tenancy with no fixed end date dictated by statute. The tenancy continues indefinitely unless validly terminated under one of the specific grounds set out in the Act.

The key practical difference is the removal of the cyclical structure. Under Part 4, a landlord could decline to renew at the end of each 6-year cycle without needing a specific ground. That option no longer exists. A TMD can only be terminated for cause, such as the tenant breaching their obligations, the landlord needing the property for personal or family use, or a genuine intention to sell. The grounds available also depend on the landlord's size classification (more on that below).

Landlord Size Classifications: Small vs Large

One of the most novel features of the 2026 reforms is the introduction of formal landlord size categories. Landlords are now classified as either “small” (owning 1 to 3 residential tenancies) or “large” (owning 4 or more). The classification is based on the total number of tenancies registered with the RTB, not the number of properties, since a single property might contain multiple lettings.

The distinction matters because certain termination grounds are only available to small landlords. For example, a small landlord can terminate a TMD on the ground that they or a family member require the property for their own occupation, or on the ground of financial hardship necessitating a sale. Large landlords cannot rely on these grounds, reflecting a policy view that larger operators should bear more risk.

Small landlords who wish to rely on a restricted ground must file a statutory declaration with the RTB confirming their size classification. If a landlord's portfolio changes (for example, they acquire a fourth property), they must update their classification. Misrepresenting your size category is an offence and can result in sanctions from the RTB.

New Construction Exemptions

To encourage development and new supply, properties that are newly built and first let after the commencement of the Act benefit from a limited exemption from national rent control. For the first letting of a newly constructed dwelling, the landlord may set the initial rent at market rate without reference to the HICP formula. However, all subsequent rent reviews on that tenancy are subject to the standard national cap.

The exemption applies only to genuinely new construction. Refurbished or renovated properties do not qualify unless the works were so extensive that the dwelling is classified as a new build under planning legislation. Conversions of commercial property to residential use may qualify, provided the local authority has issued a new housing certificate.

It is important to note that the new construction exemption applies exclusively to rent control. TMD security of tenure rules apply in full from the first day of the tenancy, regardless of whether the property is newly built. A tenant in a new-build property acquires TMD rights after six months of occupation, just like any other tenant.

What Stays the Same for Existing Tenancies

Tenants who held Part 4 rights before the commencement date automatically transition into TMD status. They do not need to complete a fresh six-month period; their existing tenure is recognised. Any notice periods that had accrued under the old regime continue to apply. If a tenant had accumulated 8 years of continuous occupation, for example, their notice entitlement is based on that full duration.

Landlords who had already validly served a notice of termination before the commencement date can proceed with that termination under the old rules, provided the notice remains valid and the stated termination date has not yet passed. If the notice was defective or the termination date has passed, the new rules apply and a fresh notice must be served under the amended Act.

Rent reviews that were already in progress under the old RPZ or non-RPZ rules will generally be governed by the law in effect at the time the notice was served. However, any new rent review notice served after the commencement date must comply with the national rent control formula, regardless of what previous reviews were based on.

Key Compliance Dates and Action Items

• Review all current leases to identify any clauses that conflict with TMD rules. Clauses purporting to limit the duration of a tenancy may now be unenforceable.
• Update your rent review calculations to use the national HICP-linked formula instead of RPZ or market comparisons.
• Determine your landlord size classification and, if you are a small landlord intending to rely on restricted grounds, prepare the necessary RTB statutory declaration.
• Ensure all new termination notices cite the correct statutory provisions under the amended Act. The old section numbers for Part 4 no longer apply.
• Check that all tenancies are properly registered with the RTB, as the size classification is based on registered tenancies.

How These Changes Affect Termination Notices

The combination of TMD rules and landlord size classifications means that termination notices are now significantly more complex. Every notice must comply with the requirements of Section 62 of the Act (as amended), state a valid ground for termination, and include the correct notice period based on the tenant's duration of occupation. For no-fault grounds such as sale of property or personal use, supporting evidence must accompany the notice or be available upon request.

Given the increased risk of disputes, we strongly recommend using a compliance checker to validate any notice before you serve it. A single missing element can render the entire notice invalid, exposing the landlord to RTB sanctions and potential damages claims.

How These Changes Affect Rent Reviews

With national rent control now in effect, every rent review must follow the same formula. The maximum permissible increase is the lower of the HICP rate or 2%. Your rent review notice must clearly state the new rent, the current rent, the date the new rent takes effect, and how the increase was calculated. The RTB must be notified of all rent changes.

Mistakes in rent review calculations are one of the most common sources of RTB complaints. Even a small mathematical error can result in a determination ordering the landlord to refund excess rent. Using a purpose-built tool to check your calculation before serving the notice is the simplest way to avoid this.