Your second IMI instalment is due by 31 August, but only if your bill tops 500 euros
Portugal's second IMI property tax instalment falls due on 31 August 2026, and only applies to owners paying more than 500 euros a year. How to check and how to pay.
If your IMI bill this year came in above 500 euros, put 31 August in your calendar. That is the deadline for the second of three instalments, and it is the one that catches the most people out, because it lands mid-holiday and nobody thinks about property tax with their feet in the sand.
The rule is worth memorising, because plenty of owners assume they have instalments they do not actually have. IMI is split according to the total due for the year: up to 100 euros, you paid it all in May; between 100 and 500 euros, it splits in two, May and November; above 500 euros it becomes three, May, August and November.
Who pays the second IMI instalment in August?
Only owners whose annual IMI exceeds 500 euros. If your bill was between 100 and 500 euros, your next payment is in November and August is not your problem. Below 100 euros, you settled the lot back in May.
What if I have lost the IMI payment notice?
Not an issue. The payment references live permanently in the IMI section of the Portal das Finanças, and there are two of them: one pays just the August instalment, the other clears everything still outstanding for the year. If you would rather not revisit this in November, use the second one.
Missing the deadline is not catastrophic, but it is expensive. Late interest starts accruing and, left unresolved, the debt moves into enforced collection — the familiar route that turns one forgotten instalment into a headache costing far more than the original tax.
Worth remembering, too, that IMI is not a fixed fate. The rate is set by each municipality, and there are exemptions and reductions tied to households with children and to renovated properties. If this year’s number surprised you, it is a nudge to look at the property’s taxable value, the same figure that shows up again when it is time to sell a home and add up the costs.
Illustrative · Photo: Mikhail Nilov / Pexels