Complete Guide to IRC Closing in Portugal: 2026

By Hugo Ribeiro, Certified Accountant · Member of the Order of Certified Accountants · HVR Business Consulting

Introduction to Year-End Closing and IRC

The year-end closing and the subsequent calculation of Corporate Income Tax (IRC) represent the most critical moment of the tax calendar for companies in Portugal. This process is not limited to simply filling out the Periodic Income Tax Return (Modelo 22), but involves an exhaustive analysis of accounting, the application of accounting standards (SNC), and their subsequent reconciliation with current tax rules. As of March 10, 2026, companies are in the middle of preparing for the 2025 closing, requiring high technical rigor to avoid fines and optimize the tax burden. The complexity of the Portuguese tax system, characterized by constant legislative changes, requires managers and certified accountants to act with a strategic vision, ensuring that all expenses are duly documented and that all available tax benefits are used lawfully.

The Relevance of Tax Transparency

In a context of increasing scrutiny by the Tax and Customs Authority (AT), the IRC closing should be seen as an exercise in transparency. The correct determination of taxable profit requires deep knowledge of the Corporate Income Tax Code (CIRC), as well as the guidelines of the Tax Authority. The objective of this guide is to provide a 360-degree view of the steps, calculations, and legal obligations that make up this annual process.

1. Determination of Taxable Profit: From Accounting to Taxation

The starting point for calculating IRC is the accounting result (profit or loss before taxes). However, not all accounting expenses are tax-deductible and not all income is taxed in the same way. Under Article 17 of the CIRC, the taxable profit of companies that primarily carry out a commercial, industrial, or agricultural activity is constituted by the algebraic sum of the net result for the period and the positive and negative equity variations verified in the same period and not reflected in that result, determined based on the accounting.

Tax Adjustments (Table 07 of Modelo 22)

To reach the tax base, it is necessary to make corrections in Table 07 of the Modelo 22 Return. These corrections are divided into variations that increase profit (such as undocumented expenses or non-deductible provisions) and variations that decrease it (such as the deduction of tax losses from previous years). One of the most sensitive points is the treatment of amortizations and depreciations, which must respect the limits established in Regulatory Decree No. 25/2009. If a company amortizes equipment at a rate higher than permitted, the excess must be added to the taxable profit.

Practical Example: Adjustment of Undocumented Expenses

Let's imagine the company "Alfa, Lda." which presents an accounting result of €100,000. During the internal audit, €5,000 in meal invoices without the company's NIF and €2,000 in traffic fines are detected. Under Article 23-A of the CIRC, these expenses are not deductible for tax purposes. Furthermore, undocumented expenses are subject to autonomous taxation at a rate of 50% (or 70% if the taxpayer is exempt or does not carry out a commercial activity).

Calculation:

Accounting Result: €100,000

(+) Undocumented expenses: €5,000

(+) Fines: €2,000

New Taxable Profit: €107,000

Additional Autonomous Taxation: €5,000 x 50% = €2,500.

2. IRC Rates and Surcharges: The Effective Cost of Tax

In Portugal, the standard IRC rate is 21% for the mainland. However, Small and Medium-Sized Enterprises (SMEs) and Small Mid-Caps benefit from a reduced rate of 17% on the first €50,000 of taxable income, as provided for in Article 87 of the CIRC. In addition to the base rate, companies must consider the Municipal Surcharge (Derrama) and the State Surcharge.

Municipal and State Surcharge

The Municipal Surcharge is levied on taxable profit and the rate is set annually by each municipality, up to a limit of 1.5%. The State Surcharge applies to companies with high profits: 3% on profits between €1.5M and €7.5M; 5% between €7.5M and €35M; and 9% for profits exceeding €35M. It is essential to check the surcharge rate of the municipality where the company has its registered office or permanent establishments.

Practical Example: Tax Calculation for an SME

The company "Beta, Lda.", certified as an SME, obtained a taxable base of €80,000 in 2025. Based in Lisbon (municipal surcharge rate of 1.5%).

Base IRC Calculation:

First €50,000 x 17% = €8,500

Remaining €30,000 (€80,000 - €50,000) x 21% = €6,300

IRC Subtotal: €14,800

Municipal Surcharge:

€80,000 x 1.5% = €1,200

Total Tax (before benefits): €16,000.

3. Tax Benefits and Investment Incentives

The year-end closing is the ideal time to apply the tax benefits provided for in the Statute of Tax Benefits (EBF) and the Investment Tax Code. These mechanisms allow for a significant reduction in the IRC collection, encouraging company capitalization and technological innovation.

RFAI and SIFIDE II

The Investment Support Tax Regime (RFAI) allows for a deduction from the tax collection of a percentage of the investment made in tangible and intangible fixed assets. On the other hand, SIFIDE II focuses on Research and Development (R&D), offering one of the most competitive benefit rates in Europe. Another crucial benefit is the Incentive for Corporate Capitalization (ICE), which allows for a deduction based on the net increase in equity, combating the bias towards debt.

Practical Example: Application of ICE

A company increased its equity by €200,000 through cash contributions from shareholders. Under Article 43-D of the EBF, the company can deduct from its taxable profit an amount corresponding to the application of a rate (usually indexed to the 12-month Euribor + spread) on this net increase, for 10 fiscal years.

If we consider a benefit rate of 5%:

Deduction from Taxable Profit: €200,000 x 5% = €10,000.

This deduction directly reduces the base on which the tax will be levied.

4. Reporting Obligations and Critical Deadlines

Compliance with deadlines is essential to avoid fines that can amount to thousands of euros. The 2025 closing calendar (occurring in 2026) follows strict rules.

  • Modelo 22: Must be submitted via electronic data transmission by the last day of May (May 31, 2026). If the end of May coincides with a weekend, the deadline is extended to the first following business day.
  • IES (Simplified Business Information): Must be submitted by the 15th day of the 7th month following the close of the fiscal year (usually July 15). The IES aggregates accounting, tax, and statistical obligations, including the deposit of accounts with the Commercial Registry Office.

Sources and Legal References

  • Corporate Income Tax Code (CIRC): Articles 17, 23, 23-A, 52, 87, and 88.
  • Statute of Tax Benefits (EBF): Article 43-D (Incentive for Corporate Capitalization).
  • Investment Tax Code: RFAI and SIFIDE II regimes.
  • Regulatory Decree No. 25/2009: Depreciation and amortization regime for IRC purposes.
  • General Tax Law (LGT): Principles for determining the taxable base.

Key Takeaways

  • Correctly calculate taxable profit following Article 17 of the CIRC.
  • Take advantage of the reduced 17% rate for SMEs on the first €50,000.
  • Submit the Modelo 22 Return mandatorily by May 31st.
  • Monitor autonomous taxations to avoid surprise tax costs.

FAQ

What is the deadline for submitting Modelo 22 in 2026?

The Modelo 22 return must be submitted by May 31, 2026, via electronic data transmission.

What is autonomous taxation in IRC closing?

These are additional rates applied to certain expenses (vehicles, representation) that the company pays even if it has a tax loss.

How does the IRC rate work for SMEs?

SMEs benefit from a reduced rate of 17% on the first €50,000 of taxable income and 21% on the surplus.

When can tax losses be deducted?

Losses can be deducted without a time limit, but only up to 65% of the taxable profit of the year in which the deduction is intended.