Mortgage Interest Relief for Landlords in Ireland (2026)

Mortgage interest is one of the largest deductible expenses available to landlords. After years of restrictions, 100% mortgage interest relief was restored from 1 January 2024. Here is everything you need to know.

The History of Mortgage Interest Relief

Pre-2009: Full mortgage interest deductible.

2009–2016: Phased reductions — at one point only 75% was deductible.

2017: Restored to 80%, then 85% in 2019, and 100% from 2024.

From 1 January 2024 onwards: 100% of mortgage interest on a residential rental property is deductible against rental income.

Who Qualifies?

You can deduct mortgage interest if:

The property is rented out as a residential letting
The mortgage is on the rental property itself (not a separate investment or home)
The tenancy is registered with the RTB — this is a legal requirement to claim the relief
You are assessable to Irish income tax on the rental income

RTB Registration is Mandatory

Revenue will disallow the mortgage interest deduction if the tenancy is not registered with the RTB. Ensure you register each tenancy at rtb.ie within one month of commencement.

What Interest Can You Deduct?

You can deduct:

Mortgage interest — the interest element of your repayments only (not capital repayment)
Arrangement fees — amortised over the loan term
Mortgage protection insurance — the portion attributable to the lender’s requirement (not your own life cover)

You cannot deduct:

Capital repayments
Interest on a loan secured on a different property
Interest on a personal loan used for renovations (a business loan secured on the property would qualify)

How to Calculate the Deduction

Your lender will send you a mortgage interest statement each year (often called a “Certificate of Mortgage Interest”). This shows the total interest paid during the tax year.

Example:

Item	Amount
Gross rental income	€18,000
Mortgage interest (from statement)	€7,200
Other allowable expenses	€2,400
Net rental profit	€8,400

The €7,200 interest is deducted in full before calculating your taxable profit.

Multi-Property Landlords

If you own multiple rental properties, each property’s mortgage interest is deducted against that property’s rental income. Losses from one property can be offset against profits from another within the same tax year.

If you make an overall rental loss after deducting all allowable expenses (including interest), that loss can be carried forward to offset future rental profits — it cannot be offset against other income such as PAYE income.

How to Claim

Self-Assessed Landlords (Form 11)

If your rental income exceeds €5,000 per year, or your total income exceeds €30,000, you must file a Form 11 via Revenue Online Service (ROS).

Steps:

Obtain your mortgage interest certificate from your lender
Calculate total rental income for the year
List all allowable deductions (mortgage interest, insurance, repairs, management fees, etc.)
Enter the net rental profit on your Form 11
File by 31 October (or mid-November for ROS filers)

PAYE Workers with Smaller Rental Income

If your rental income is under €5,000 and your total income is under €30,000, you can declare rental income via myAccount on Revenue’s website rather than filing a full Form 11.

Interaction with Other Reliefs

Pre-Letting Expenses

Interest accrued while the property was vacant before the first letting can be deducted in the first year of rental — provided the property was actively being prepared for letting.

Capital Gains Tax

Mortgage interest is not deductible against CGT when you sell the property. Only enhancement expenditure (capital improvements) can be offset against CGT. Keep records of interest separately from capital works for this reason.

Section 23 Relief (Legacy)

If you purchased a qualifying property between 1999–2011 under the Section 23 scheme, special rules apply. These reliefs are being wound down — consult an accountant.

Tips for Landlords

Keep your mortgage interest certificate — Revenue may request it in an audit
Register every tenancy with the RTB — failure to do so disallows the deduction
Track interest monthly — useful if you sell mid-year and need to apportion
Refinancing — if you remortgage to release equity for non-property purposes, only the interest on the original balance used for the rental property remains deductible
Joint ownership — each owner deducts their share of interest proportionate to their ownership stake

Useful Resources

This guide is for informational purposes only. Tax rules can change — consult a qualified accountant or tax advisor for advice specific to your circumstances.