FiscalFox editorial team · Sources checked 13 October 2026
Start with FIFO, then check recent purchases
Normally, the oldest shares of the same class are matched first: first in, first out. Shares purchased in the four weeks before a sale are identified first under the special rule; the excess quantity follows FIFO.
Suppose an old lot contains ten shares costing €100, and a recent lot contains two shares costing €40. A sale of three shares within four weeks of that recent purchase first uses the two recent shares and then one old share. The matched cost is €50 before any additional relevant adjustments.
A later repurchase can restrict a loss
A loss followed by a repurchase within four weeks may only offset gains on those replacement shares. A partial repurchase restricts the corresponding fraction. This is a separate step from deciding which acquisition costs match the original sale.
That is why a loss near year-end can need records from the following January. A transaction dated in January does not, by itself, prove that the intervening history is complete.
Read the workings in your report
FiscalFox's evidence pack identifies the purchase matched to each sale and the quantity and cost consumed. Keep the matching schedule alongside the original exports. Check any unresolved acquisition or execution evidence against the broker record.
The Irish engine is separate from the UK engine. A UK Section 104 pool should not be reused as an Irish acquisition ledger. Shares, funds and employee-share income also need their appropriate treatment; the ordinary-share report has an explicit scope.