Federal Tax Debt Calculator (SICALC)

Principal, penalty, and SELIC interest

A federal tax paid late is not corrected by a single index, but by a combination of three parts. The first is the principal, the original amount of the tax. The second is the late payment penalty, 0.33% per day of delay, which grows up to the 20% cap on the principal (art. 61 §2 of Law 9.430/1996). The third is the default interest, equivalent to the accumulated SELIC rate.

SELIC interest starts running from the month after the due date and accumulates month by month, with an added 1 percentage point in the month of actual payment (art. 61 §3). The accumulation is a sum of the monthly rates, not compound interest: month by month, each competency's percentage is simply added to the running total, without accruing on top of the interest already computed for prior months. One key point: interest applies only to the principal, never to the penalty, the penalty is a separate percentage. This is the same logic as SICALC, the Federal Revenue Service's official tool.

• Principal: the original amount of the tax.
• Late penalty: 0.33%/day, 20% cap (art. 61 §2).
• Interest: sum of the monthly SELIC rates + 1 percentage point in the payment month (art. 61 §3).
• No SELIC at all if payment falls in the same calendar month as the due date.
• Interest applies only to the principal, not to the penalty.

Adding the late penalty and accumulated SELIC

Imagine a R$ 10,000 tax paid late. The late penalty rises 0.33% per day until it locks at 20%, that is, R$ 2,000 at most. Interest also accrues on the principal: if the accumulated SELIC for the period (from the month after the due date to the month before payment, plus 1% in the payment month) came to, for illustration only, 15%, the interest would be R$ 1,500. The updated total would be R$ 10,000 + R$ 2,000 + R$ 1,500 = R$ 13,500. The SELIC percentages are exactly those published by the BCB; the number in this example only illustrates the sum.

The calculator does this automatically: it identifies the months between the due date and payment, adds up each month's SELIC (SGS series 4390), adds 1 percentage point for the payment month, and sums the chosen penalty. If the due date and payment fall in the same calendar month, it automatically zeroes out the SELIC interest. The result breaks out principal, penalty, and interest separately, so you can check each part.

Installment plans, estimated months, and what to verify

This tool computes voluntary debts and those assessed by audit, but it does not replace the calculation of active installment plans. In programs such as PERT or REFIS the penalty may be reduced or eliminated and interest follows its own rules, in those cases, use the official installment system. The assessment penalty (75% or 150%) applies only when the debt is found by the RFB through a tax assessment, not on voluntary payment.

SELIC is official and verified only through the date shown in the tool (BCB SGS series 4390). Months not yet published are estimated with the last known rate and flagged as 'estimated', rather than being treated as zero. For that reason, and because SELIC changes monthly, treat the total as an educational estimate and confirm the figures in SICALC/RFB before paying.

• Do not use for active installment plans (PERT, REFIS).
• Assessment penalty: only on a tax assessment (75% or 150%).
• Same-month payment: no SELIC, only the penalty.
• Months without published SELIC show as 'estimated'.
• Confirm the total in the RFB's SICALC.