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IBKR CGT payment dates in Ireland: 15 Dec and 31 Jan

Updated: 21/10/2026

Irish CGT on IBKR share sales is paid before you file: 15 December and 31 January. How to work out each payment, pay on ROS and avoid daily interest.

In Ireland you pay Capital Gains Tax on share sales before you file the return. Gains from disposals between 1 January and 30 November must be paid by 15 December of the same year, and gains from December disposals by 31 January of the following year; the figures are then reported on Form 11 or Form CG1 by 31 October.

• Initial period: disposals from 1 January to 30 November. Pay by 15 December.
• Later period: disposals in December. Pay by 31 January of the next year.

For tax year 2025 those dates were 15 December 2025 and 31 January 2026. If you have sold shares at IBKR during 2026, the next payment, for sales from January to November 2026, is due on 15 December 2026.

The date that counts is the date the sale was agreed — the trade date — not the date the cash settled. A trade on 30 November that settles in December belongs to the initial period.

For each period, take the gains on shares you sold, subtract the losses from that same period, and apply 33%. The €1,270 annual exemption is normally used against the first gains of the year, so it usually reduces the 15 December payment. Losses carried forward from earlier years can also be used.

Only shares and similar assets under CGT belong here. Exit tax on EU-domiciled ETFs, tax on dividends and tax on interest are not paid on these dates; they are settled with the Form 11 balance.

Niamh made these sales at IBKR in 2025, all already converted to euro:

• March: gain of €4,000
• July: loss of €1,000
• December: gain of €2,500

Initial period: €4,000 − €1,000 = €3,000; minus the €1,270 exemption leaves €1,730. At 33% that is €570.90, due by 15 December 2025.

Later period: €2,500 × 33% = €825, due by 31 January 2026.

Total CGT for 2025: €1,395.90, reported later on her Form 11.

1. Export an IBKR Activity statement covering 1 January to 30 November (or the full year for the December payment); custom date ranges are available under Performance & Reports, then Statements.
2. Match each sale with its purchases first in, first out, and convert both sides to euro at the rate for each date.
3. Net gains against losses for the period and apply the exemption if it has not been used yet.
4. Multiply by 33% to get the amount for that period.
5. Pay through the Capital Gains Tax payment option in ROS, or in myAccount if you are not registered for ROS, choosing the correct year and period.
6. Keep the payment confirmation, then report the gains, losses and exemption on Form 11 (or Form CG1) by 31 October of the following year.

Late CGT carries interest of 0.0219% per day, roughly 8% a year. If Niamh had paid her €570.90 a hundred days late, the interest would be €570.90 × 0.0219% × 100 = about €12.50. That sounds small, but it grows with the amount and the delay, and a late return can add a surcharge of 5% or 10% of the tax on top.

• Paying all the CGT with the return in October, as if it were income tax. By then the 15 December payment is ten months late.
• Using settlement dates, which can push a late-November or late-December trade into the wrong period.
• Including EU ETF gains in the CGT payment. Those are taxed at the exit-tax rate and paid with Form 11.
• Forgetting a sale because the money stayed in the account and was reinvested. A sale is a disposal whether or not you withdraw the cash.
• Assuming no payment is needed because a December loss will cancel an earlier gain. A loss in the later period does not reduce the 15 December payment, which must be made on time.

The 15 December deadline arrives quietly, weeks before most people think about tax, and the interest starts the next day. Upload your IBKR statement to Brokers.tax to see your share gains for the year in euro, period by period, so you know exactly what to pay before the date passes.