Capital Gains Tax Deadline: What You Need to Know Before 15th December 2025

If you’ve sold, transferred, or otherwise disposed of an asset in 2025 that resulted in a taxable gain, the next key date in your financial calendar is 15th December 2025 — the main payment deadline for Capital Gains Tax (CGT) in Ireland.

Understanding the rules — and acting early — can help you avoid unnecessary penalties and ensure you remain fully compliant with Revenue requirements.

Below, we break down what taxpayers need to know.

What Is Capital Gains Tax?

Capital Gains Tax (CGT) is the tax charged on the profit (or gain) when you dispose of an asset.
Common taxable disposals include:

Selling property that is not your primary residence
Disposing of shares or investments
Selling a business or business assets
Gifts of assets (in certain cases)

CGT is charged at 33% unless specific reliefs or exemptions apply.

Key Deadline: 15th December 2025

If you made a taxable gain between 1 January and 30 November 2025, your CGT must be paid by 15 December 2025.

There is one important exception:

📌 If the disposal took place in December 2025, the deadline to pay CGT is
31st January 2026.

These deadlines relate to payment of CGT — your detailed CGT return is due later, as part of your Form 11 tax return filing.

What You Need to Do Now

To ensure you’re meeting Revenue obligations, take the following steps as soon as possible:

1. Calculate any gains made in 2025

Determine the difference between:

The sale price (or market value), and
The original cost of acquiring the asset (adjusted for allowable expenses)

2. Determine your CGT liability

Apply the 33% CGT rate and consider whether any reliefs apply, such as:

Entrepreneur Relief
Retirement Relief
Principal Private Residence Relief
Transfer of business assets within family structures

Many taxpayers miss opportunities here, so review these carefully.

3. Pay Revenue by the 15th December deadline

Late payments may incur:

Interest charges
Possible penalties
Cash-flow difficulties if tax is unexpectedly high

Act early to avoid unnecessary stress or last-minute issues.

What If You’re Unsure Whether a Disposal Is Taxable?

It’s common for taxpayers to be uncertain — especially when dealing with:

Shares sold through investment apps
Property transfers within families
Partial disposals
Cryptoasset transactions
Business or partnership exits

If there’s any uncertainty, seeking clarity now can help avoid Revenue queries or miscalculations later.

How WDA Can Help

Understanding CGT can feel complicated — especially if multiple assets, reliefs, or historic costs are involved.
Our team at Whelan Dowling & Associates can help you: