Civil debts use the legal rate of 4%. For commercial transactions between businesses, the rate changes every six months (10.15% in the first half of 2026). For tax debts or another situation, choose “Other rate” and enter the rate in force.
| Amount owed | €1,000.00 |
| Interest per day late (4%/yr) | €0.11/day |
| Interest on 90 days late | €9.86 |
| = Total to pay (debt + interest) | €1,009.86 |
Educational estimate, not legal, tax or financial advice. It computes simple late-payment interest (amount × rate × days ÷ 365). Confirm the applicable rate and the date from which interest is due.
Late-Payment Interest Calculator (Portuguese Juros de Mora) by Calculadora Capital