To fill out and file Form CG1, download the paper return from Revenue.ie, calculate your chargeable gain after allowable costs and reliefs, complete the seven pages in order, pay the tax by the relevant December or January deadline, and post the signed form to Revenue in Ennis by October 31 of the year after the disposal. The form is the Capital Gains Tax return used by individuals who don’t already submit an annual self-assessment.
Who Uses Form CG1
Form CG1 is for individuals who don’t file a Form 11 or an online Form 12. In practice, that’s mostly PAYE employees and pensioners who have a one-off disposal during the year. If you already file a Form 11, or you use Form 12 through myAccount, report your capital gains there instead.1Revenue Irish Tax and Customs. Capital Gains Tax (CGT) on the Disposal of an Asset
File even when no tax is due. Losses, disposals wiped out by relief, and gains covered by the annual exemption all still need to go on the return.2Revenue. Form CG1 – Capital Gains Tax Return and Self-Assessment 2025
What to Work Out Before You Start
The form asks for numbers, not narrative. Do the arithmetic first, then transcribe.
Take the sale proceeds, subtract the original purchase price, and subtract allowable costs. Allowable costs include solicitor fees, stamp duty, auctioneer or estate agent commissions, and the cost of improvements you made to the asset during ownership. Keep every invoice and receipt.
If you bought the asset before 2003, indexation relief may adjust the purchase price and pre-2003 improvement costs upward using Revenue’s multiplier tables. Indexation was abolished for disposals from 2003 onward, so it only applies to expenditure incurred before that cutoff.3Revenue. Part 19-02-13 – Indexation (S-556)
From the resulting gain, deduct the annual personal exemption of €1,270. Each individual gets this exemption per tax year. If you’re married or in a civil partnership, you each have your own €1,270, but an unused exemption cannot be transferred to your spouse. The standard CGT rate of 33% applies to whatever remains.4Revenue Irish Tax and Customs. Capital Gains Tax (CGT) on the Disposal of an Asset
Capital losses from earlier years can be carried forward and offset against current gains. The form has dedicated fields for these carry-forward losses.
Have your Tax Reference Number to hand. Revenue asks for it on every page of the form.
Reliefs to Identify Before Completing the Form
Each relief has its own section on the form, so know which ones apply before you begin.
Principal Private Residence Relief
If a property was your only or main home for the entire period of ownership, the gain is fully exempt. The exemption covers up to one acre of surrounding land, excluding the site of the house itself. The last 12 months of ownership automatically count as occupation, which helps if you moved into a new home before selling the old one.5Revenue Irish Tax and Customs. Principal Private Residence (PPR) Relief
Partial relief applies where you didn’t live there for the whole ownership period, or where part of the property was used for business. Relief is proportional to the time you lived there and the floor space used as your home. Certain absences still count as occupation: periods when your employer required you to live elsewhere (up to four years), time spent working entirely outside Ireland, and stays in hospitals, nursing homes, or retirement homes.5Revenue Irish Tax and Customs. Principal Private Residence (PPR) Relief
Spousal and Civil Partner Transfers
A transfer to a spouse or civil partner while you’re living together is fully exempt. The receiving spouse is treated as having acquired the asset at its original cost, so no gain arises on the transfer itself. Separated couples can still use the exemption if the transfer is made under a separation agreement or court order.6Revenue Irish Tax and Customs. Transferring Assets Between Spouses or Civil Partners
Revised Entrepreneur Relief
Qualifying business disposals are taxed at 10% rather than 33%, up to a lifetime limit. From January 1, 2026, that limit rises to €1.5 million (up from €1 million). Gains realized between 2016 and 2025 count toward the original €1 million cap; disposals from 2026 onward can access the higher ceiling. You need to have owned at least 5% of the ordinary share capital for a continuous three-year period, and to have spent more than 50% of your working time in the business in a managerial or technical role for at least three continuous years within the five years before disposal. Investment assets and development land don’t qualify.7Forvis Mazars. Entrepreneur Relief: Lifetime Limit Increase
Other Exemptions
Assets passed on after death carry no CGT charge; they’re treated as acquired at market value on the date of death. Retirement Relief may apply if you’re 55 or older and disposing of business or farm assets, and you don’t actually have to retire to claim it. A site transferred to a child for building a home is exempt if it’s under one acre and worth €500,000 or less. Private motor cars, betting and lottery winnings, government stocks, and moveable tangible property producing gains of €2,540 or less are outside the CGT net.8Citizens Information. Capital Gains Tax
Completing the Seven Pages
There is no online version. Download the PDF from the gains, gifts, and inheritance section of Revenue.ie. The 2025 return, covering disposals between January 1 and December 31, 2025, runs to seven pages.2Revenue. Form CG1 – Capital Gains Tax Return and Self-Assessment 2025
Page 1 takes your contact details, your agent’s details if you’re using a tax advisor, and the declaration. The deadlines and surcharge rules are printed here for reference.
Page 2 is the core capital gains section: asset descriptions, number of disposals, dates, aggregate sale proceeds, and initial relief claims for PPR relief, site-to-a-child relief, and Retirement Relief.
Page 3 covers spousal and civil partner relief claims, deferral claims, and the calculation of losses and chargeable gains.
Page 4 breaks the net gain down by tax rate. The form accommodates gains taxed at 33%, 40%, 15%, and 10% (Entrepreneur Relief). The €1,270 personal exemption is deducted here, along with any carry-forward losses from prior years.
Page 5 handles the expression of doubt (if you’re unsure about the tax treatment of a particular item), double taxation relief for gains taxed in another country, and your bank details for any repayment.
Pages 6 and 7 are the self-assessment panel and final declaration, including the balance of tax payable or overpaid.
If you send the completed form to Revenue by August 31, they’ll do the self-assessment for you, which is useful if you’re uncertain about the final figures. Otherwise, complete the self-assessment yourself. Leaving it out triggers a €250 penalty.2Revenue. Form CG1 – Capital Gains Tax Return and Self-Assessment 2025
Pay the Tax Before You File the Form
The payment deadline comes months before the return is due, and this is where people slip. The year is split into two payment periods:1Revenue Irish Tax and Customs. Capital Gains Tax (CGT) on the Disposal of an Asset
- Disposals from January 1 to November 30: CGT payment is due by December 15 of the same year.
- Disposals in December: CGT payment is due by January 31 of the following year.
Sell shares in March 2026, and the tax is due by December 15, 2026, but the Form CG1 return isn’t due until October 31, 2027. Miss the payment deadline and interest accrues daily at 0.0219%, roughly 8% per year, from the original due date until the tax is paid in full.9Revenue Irish Tax and Customs. Corporation Tax (CT) Payment and Filing
Pay electronically through myAccount or the Revenue Online Service (ROS). If you haven’t registered for CGT on myAccount, sign in, go to Tax Registrations under the Manage My Record tile, and select Register on the CGT line.1Revenue Irish Tax and Customs. Capital Gains Tax (CGT) on the Disposal of an Asset
Through myAccount, pay by debit card, credit card, or a single debit instruction from your bank account. Allow at least three working days for the payment to reach the Collector-General. If it lands after the deadline, interest runs from the original due date regardless of when you initiated the transfer.10Revenue Commissioners. Capital Gains Tax (CGT) Payment
Posting the Return
The signed Form CG1 goes to Revenue by post. Use any envelope and write “Freepost” above the return address; no stamp is needed.1Revenue Irish Tax and Customs. Capital Gains Tax (CGT) on the Disposal of an Asset
Revenue Commissioners
Government Offices
Kilrush Road
Clonroad Beg
Ennis
Co. Clare
The filing deadline is October 31 of the year following the disposal. For assets sold at any point in 2025, the form is due by October 31, 2026.2Revenue. Form CG1 – Capital Gains Tax Return and Self-Assessment 2025
What Happens if You File Late
A late return brings a surcharge on top of the tax due:2Revenue. Form CG1 – Capital Gains Tax Return and Self-Assessment 2025
- Up to two months late: 5% of the tax due, capped at €12,695.
- More than two months late: 10% of the tax due, capped at €63,485.
Watch the Local Property Tax trap. If you file Form CG1 on time but you’re not up to date on LPT, Revenue treats the return as if it were more than two months late and applies the 10% surcharge up to the €63,485 cap. The surcharge is reversed once you bring your LPT current, and even then it’s capped at the amount of LPT you owed.2Revenue. Form CG1 – Capital Gains Tax Return and Self-Assessment 2025
Records to Keep
Hold all documentation for at least six years after the transaction: purchase contracts, sale agreements, solicitor and auctioneer invoices, receipts for improvement works, and confirmation of your CGT payment.11Revenue Irish Tax and Customs. Keeping Records
If Revenue opens an inquiry or audit, the six-year clock extends until the matter is resolved. Revenue’s guidance specifies keeping originals rather than copies.