Is Your Rent Increase Legal? How to Check in 5 Minutes

You’ve just received a letter from your landlord: they’re increasing your rent. Your heart sinks. But before you panic, take a breath—not all rent increases are legal, and you have more power than you might think.

The Quick Check

To determine if your rent increase is legal, you need to answer three questions:

When was your rent last reviewed?
Is your property in a Rent Pressure Zone (RPZ)?
What percentage is the increase?

Let’s break each down.

Question 1: When Was Your Rent Last Reviewed?

Your landlord cannot increase rent more than once every 12 months (or 24 months for new tenancies that started after 11 December 2021).

If it’s been less than 12 months since your last increase, the new increase is likely invalid—regardless of the amount.

Check: Look at your previous rent notices or bank statements to find the date of your last increase.

Question 2: Is Your Property in an RPZ?

Rent Pressure Zones cover most of Ireland, including:

All of Dublin
Cork City and suburbs
Galway City
Limerick City
Most of the Greater Dublin Area
Many other urban areas

You can check the official list at RTB.ie/rpz.

Why it matters: In RPZ areas, rent increases are capped. Outside RPZs, landlords have more flexibility (but still can’t charge more than market rate).

Question 3: What’s the Increase Percentage?

In RPZ areas, rent can only increase by a maximum of 2% per year.

Here’s how to calculate it:

Increase % = ((New Rent - Current Rent) / Current Rent) × 100

Example: If your rent is going from €1,500 to €1,600:

Increase: €100
Percentage: (100 / 1500) × 100 = 6.67%
This exceeds the 2% cap and would be illegal in an RPZ

The maximum legal new rent would be: €1,500 × 1.02 = €1,530

Use our Rent Increase Calculator to do this calculation automatically.

What If Your Increase Is Illegal?

If your increase exceeds the legal limits, you have options:

Step 1: Respond in Writing

Write to your landlord explaining why you believe the increase is invalid. Keep it factual:

“I have reviewed the proposed rent increase and note that [reason: too soon / exceeds RPZ cap / etc.]. Under the Residential Tenancies Acts, this increase does not appear to comply with current regulations. I would appreciate if you could review this and respond.”

Step 2: Don’t Pay the Illegal Increase

Continue paying your current rent amount. You’re legally entitled to do this while the dispute is ongoing.

Step 3: Contact Threshold

Threshold offers free advice to tenants. Call them at 1800 454 454 to discuss your situation.

Step 4: File with the RTB

If your landlord doesn’t back down, you can file a dispute with the Residential Tenancies Board. The process is:

Submit an application online at RTB.ie
Pay the filing fee (€15)
Attend mediation or tribunal hearing
Receive a binding decision

Many landlords withdraw improper increases once an RTB case is filed—they know they’ll lose.

Valid Reasons for Larger Increases

There are limited circumstances where a landlord might argue for a larger increase:

Substantial renovations: If significant improvements were made to the property
Initial low rent: If the rent was well below market rate when tenancy started
Outside RPZ: If the property genuinely isn’t in an RPZ

Even in these cases, the landlord must follow proper procedures and can be challenged.

Required Notice Period

Regardless of the amount, your landlord must give you 90 days written notice of any rent increase. If they give less notice, the increase is invalid.

The notice must also include specific information as required by law.

Protect Yourself

Keep all correspondence: Save letters, emails, and texts
Pay rent by traceable method: Bank transfer, not cash
Know your tenancy start date: This affects your rights
Document everything: Photos, dates, conversations

The Bottom Line

Many tenants accept rent increases without questioning them. But with RPZ caps at just 2%, even small illegal increases add up to thousands of euros over time.

If something doesn’t seem right, it probably isn’t. Check the numbers, know your rights, and don’t be afraid to push back.

Quick tool: Use our Rent Increase Calculator to check your specific situation in seconds.

Need personalised advice? Contact Threshold at 1800 454 454 (free) or the RTB at 0818 303 037.