FiscalFox editorial team · Product lead: Grant Sloane · Updated
Calculate Irish investment taxEstablish a realised, evidenced loss
Compare the disposal proceeds with the allowable cost matched to that sale. A broker portfolio showing a negative unrealised return is not itself a disposal loss. Missing purchase evidence cannot be replaced with a current market value.
FiscalFox shows which purchase lots support each disposal. Resolve a cost or corporate-action issue against the affected sale before treating the amount as a loss available elsewhere.
Check repurchases around the sale
Irish share rules include special treatment for purchases within the preceding four weeks and restrictions after a loss followed by repurchase within four weeks. The matching question and the loss-availability question are separate.
A sale late in December can require relevant January records. Keep later purchase evidence where it affects the restriction. Do not turn every repurchase-related amount into a general loss against unrelated holdings.
Sources: Revenue: share identification
Retain the carry-forward trail
Revenue allows unused allowable capital losses to be carried forward against later available gains. Keep the earlier return and computation showing what arose, what was used and what remained.
Use the evidenced opening amount in the selected-year review. Do not carry forward the original gross loss again after part was used. FiscalFox tracks restricted share losses separately from general amounts brought forward.
Sources: Revenue: capital losses
Reconcile the annual result across brokers
A loss and gain can arise at different brokers. Bring relevant records into one calculation rather than using an exemption independently on each account. Preserve the disposal-date breakdown where gains have different rates.
The example below is a simple 2025 calculation with general allowable losses. It is not a rule for a restricted loss, connected-party transaction or fund disposal. Those cases require their own treatment.
Keep fund losses and income outside ordinary share losses
Do not use an ETF loss as an ordinary CGT loss just because it is listed beside shares in an export. Establish the fund regime and keep its calculation separate. A dividend payment is also not a capital gain to offset in this schedule.
Download the annual share computation and matching workings to support the return, including years with no tax payable. Paying nothing does not in itself remove the filing requirement.
Sources: Revenue: paying and filing CGT
Illustrative 2025 annual loss reconciliation
All amounts are euro, losses are generally allowable and there are no repurchase restrictions or other gains.
| Record or figure | Value |
|---|---|
| Share gains | €5,000.00 |
| Allowable current-year share losses | €1,000.00 |
| Net gain | €4,000.00 |
| Personal exemption | €1,270.00 |
| Taxable gain | €2,730.00 |
| 2025 CGT at 33% | €900.90 |
Questions and answers
Can I carry forward unused capital losses?
Unused allowable capital losses can be carried forward under Revenue’s rules. Keep the earlier computation and the amount already used.
Does every loss after selling and rebuying count as a general loss?
No. Four-week share repurchase restrictions can limit its use to gains on replacement shares.
Is a fall in my unsold portfolio a claimable disposal loss?
An unrealised market fall is not itself a realised share-disposal loss.
Official sources
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