A Company's Tax Obligations: The Definitive Guide to the Annual Calendar in Portugal

Managing a company's tax obligations in Portugal in 2026 requires adherence to a strict calendar, including the monthly submission of the SAF-T file by the 5th, the periodic VAT return (monthly or quarterly) by the 20th of the relevant month, and the submission of the Corporate Income Tax (CIT) return (Model 22) by May 31st. Failure to meet these deadlines results in fines that can amount to tens of thousands of euros, directly impacting the company's financial health.

By Hugo Velez Ribeiro, Certified Accountant (OCC nº 64356) · 31/07/2026

Tax compliance is a fundamental pillar for the sustainability and success of any business in Portuguese territory. The national tax system, while robust, is characterized by a multitude of declarations, payments, and communications with different deadlines throughout the year. For a manager or entrepreneur, mastering this calendar is not just a legal obligation but a strategic management tool that prevents fines, optimizes cash flow, and ensures a transparent relationship with the Tax and Customs Authority (AT). This detailed guide serves as an exhaustive roadmap, covering the main monthly, quarterly, and annual tax obligations, from VAT and CIT to Social Security, so that your company can navigate the 2026 fiscal year with confidence and rigor.

Monthly Obligations: The Foundation of Continuous Compliance

The monthly routine forms the backbone of a company's tax compliance. Strict adherence to these recurring deadlines is essential to avoid the accumulation of fines and late payment interest, keeping the company's tax situation regularized. The two most critical obligations are the submission of the Periodic VAT Return (for the monthly regime) and the Monthly Remuneration Statement (DMR).

Periodic VAT Return (DP-IVA) - Monthly Regime

Companies with a turnover exceeding €650,000 in the previous calendar year, or those that opt for this regime, are required to submit the DP-IVA monthly. This return calculates the tax charged on sales and services and the tax incurred on purchases, resulting in an amount payable to the State or a credit in favor of the company. The deadline for the electronic submission of the DP-IVA is the 20th of the second month following the operations, as stipulated in Article 41 of the VAT Code (CIVA). The corresponding payment must be made by the 25th of the same month.

Practical Case: VAT Calculation and Deadlines

The company "Tecnologia Avançada, Lda.", under the monthly VAT regime, carried out the following operations in January 2026:

• Product sales: €80,000 + 23% VAT = €18,400 of output VAT.
• Purchase of raw materials: €30,000 + 23% VAT = €6,900 of deductible input VAT.
• Electricity and communication expenses: €2,000 + 23% VAT = €460 of deductible input VAT.

The tax to be paid to the State is calculated as: Output VAT - Deductible VAT = €18,400 - (€6,900 + €460) = €11,040. The company must submit the January DP-IVA by March 20, 2026, and make the payment of €11,040 by March 25, 2026.

Monthly Remuneration Statement (DMR)

The DMR is a mandatory declaration for all entities that pay employment income. Its purpose is to report to the AT the income paid, the withholdings at source for Personal Income Tax (IRS), and the contributions to Social Security (from both the employer and the employees). The deadline for its submission is the 10th of the month following the one to which the income relates. The payment of Social Security contributions and the remittance of the withheld IRS to the State must be made by the 20th of that same month. Failure to submit the DMR can result in fines starting at €250, according to the General Regime of Tax Infractions (RGIT).

Communication of Invoicing: The SAF-T (PT) File

The digitalization of the Portuguese tax administration has made the electronic communication of documents a standard and mandatory procedure. The SAF-T (PT) file, an acronym for Standard Audit File for Tax Purposes - Portuguese version, is the centerpiece of this system. It is a file in XML format that exports a predefined set of invoicing data from a computer system to the Tax Authority.

The Nature and Deadline of the Invoicing SAF-T

All companies with headquarters or a permanent establishment in Portugal that use certified invoicing software are required to communicate the elements of the invoices issued monthly. This communication is done by submitting the SAF-T (PT) file on the e-fatura portal. The communication of the SAF-T(PT) file for invoicing must be carried out by the 5th of the month following the issuance of the documents, according to Article 3 of Decree-Law No. 198/2012. This deadline was recently changed, and its observance is critical. Failure or delay in this communication is punishable by a fine that can range from €200 to €10,000, depending on the company's turnover and the length of the delay.

Step-by-Step Guide for a Correct Submission

1. File Extraction: At the end of each month, the first step is to generate the SAF-T (PT) file from the AT-certified invoicing software. This software must ensure the integrity and correct structure of the file.
2. Validation: Before submission, it is highly recommended to use the AT's own validation application to check if the file contains any structural or content errors that could lead to its rejection.
3. Submission on the e-fatura Portal: Access the company's area on the Tax Portal, navigate to the e-fatura service, and submit the validated file.
4. Archive the Proof of Submission: After a successful submission, the portal generates a receipt. It is essential to save this digital document as proof of compliance.

Common Errors to Avoid

One of the most frequent errors is using non-certified software, which invalidates any communication. Another common mistake is the incorrect filling of customer data, such as an invalid VAT number, which causes the file to be rejected. It is also crucial to ensure that all fiscally relevant documents (invoices, invoice-receipts, debit and credit notes) are included in the file. An omission, even if unintentional, is considered an infraction. For example, if a company issues 200 invoices and 5 credit notes in April 2026, the SAF-T to be submitted by May 5, 2026, must contain all 205 documents. Forgetting the credit notes would result in a file inconsistent with the accounting records and subject to a penalty.

Corporate Income Tax (CIT): Payments and Declarations

Corporate Income Tax (CIT or IRC in Portuguese) is the tax levied on a company's profits. Its management unfolds in two main aspects throughout the year: advance payments (Payments on Account and Additional Payments on Account) and the submission of the annual income tax return (Model 22 and IES).

CIT Payments on Account (PPC)

PPCs are advance tax payments, calculated based on the CIT assessed in previous years, which aim to align tax collection with the moment profits are generated. According to Article 104 of the Corporate Income Tax Code (CIRC), these payments are due by companies that reported taxable profit in the previous tax period (n-2). The deadlines for these payments in 2026 are: July 31, September 30, and December 15. The amount payable corresponds to 80% of the CIT assessed in n-2 for companies with a turnover up to €500,000, and 95% for higher turnovers.

Practical Case: PPC Calculation

The company "Comércio Global, SA" had, in its 2024 tax period, a turnover of €1,200,000 and an assessed CIT of €50,000. In 2026, it will have to make Payments on Account. The calculation is as follows:

• Calculation basis: €50,000 (CIT assessed in 2024).
• Applicable percentage (turnover > €500,000): 95%.
• Total value of PPCs for 2026: €50,000 * 95% = €47,500.
• Value of each installment: €47,500 / 3 = €15,833.33.

The company must pay €15,833.33 by July 31, €15,833.33 by September 30, and €15,833.34 by December 15, 2026. It is possible to suspend the third PPC if the company anticipates that the payments already made are sufficient to cover the CIT due at the end of the year.

The Annual CIT Returns: Model 22 and IES

After the end of the fiscal year, companies must determine their taxable income and submit the annual returns that formalize this calculation with the AT and other entities.

Periodic Income Tax Return Model 22

Model 22 is the central CIT return. It is through this form that the company declares its taxable profit (or loss), calculates the tax due, and settles its accounts with the State, deducting the Payments on Account and withholdings at source already made. For companies whose tax period coincides with the calendar year, the deadline for submitting Model 22 is May 31 of the following year, according to Article 120 of the CIRC. The payment of the self-assessed CIT, if any, must also be made by this date.

Practical Case: From Accounting Profit to CIT

The company "Serviços Eficientes, Lda." ended the 2025 fiscal year with an accounting profit before tax of €150,000. In the tax analysis, €10,000 in fines and penalties (non-deductible expenses) and €5,000 in non-fiscally accepted provisions were identified. The taxable profit is calculated as follows:

• Accounting Profit: €150,000
• Positive Adjustments (non-deductible expenses): €10,000 + €5,000 = €15,000
• Taxable Profit: €150,000 + €15,000 = €165,000
• CIT liability (general rate of 20% applicable to the 2025 tax period — art. 87(1) of the CIRC, as amended by Law 45-A/2024 of 31 December; for tax periods starting in 2026 the rate is 19%, art. 87 of the CIRC as amended by Law 64/2025 of 7 November, and art. 3(2) of the same law): €165,000 * 20% = €33,000
• Municipal Surtax (e.g., 1.5% on taxable profit): €165,000 * 1.5% = €2,475
• Total CIT to pay: €33,000 + €2,475 = €35,475

This calculation will be reported on the Model 22 to be submitted by May 31, 2026.

Simplified Business Information (IES) / Annual Statement

The IES is an annual reporting obligation that simplifies the delivery of information to various entities. Established by Decree-Law No. 8/2007, of January 19, the IES combines into a single act the submission of the annual accounting and tax information statement to the AT, the registration of the annual accounts with the commercial registry offices, and the delivery of statistical information to the National Statistics Institute (INE) and the Bank of Portugal. The submission of the IES/Annual Statement by July 15 is crucial as it consolidates the obligations of filing annual accounts and tax and statistical returns. Its submission is exclusively electronic and requires the signature of a Certified Accountant. The complexity of its annexes (such as Annex A for the balance sheet and income statement, and Annexes L to O to detail assets, liabilities, etc.) requires careful and timely preparation, being one of the core services provided by an accounting firm.

Quarterly Obligations: The VAT Regime for SMEs

Not all companies share the same frequency of obligations. For small and medium-sized enterprises (SMEs), the quarterly VAT regime offers a less intense cadence, easing the monthly administrative burden. This regime is applicable to companies whose turnover in the previous calendar year did not exceed €650,000. However, opting for the monthly regime is always possible.

Deadlines and Operation of the Quarterly VAT Regime

Under the quarterly regime, the Periodic VAT Return (DP-IVA) is submitted four times a year. The submission deadlines are designed to provide sufficient time to calculate the values after the close of each quarter. Companies with a turnover of less than €650,000 can be included in the quarterly VAT regime, submitting the return by the 20th of the second month following the quarter. The submission and payment deadlines for 2026 are:

• 1st Quarter (Jan-Mar): Submission by May 20 / Payment by May 25.
• 2nd Quarter (Apr-Jun): Submission by August 20 / Payment by August 25.
• 3rd Quarter (Jul-Sep): Submission by November 20 / Payment by November 25.
• 4th Quarter (Oct-Dec): Submission by February 20, 2027 / Payment by February 25, 2027.

It is essential to note that the deadline for the last quarter of the year carries over to the following year.

Practical Case: Quarterly VAT Management

A graphic design startup, "Criatividade Ilimitada, Lda.", is on the quarterly regime. In the 2nd quarter of 2026 (April to June), it recorded the following movements:

• Total service invoicing: €60,000 + 23% VAT = €13,800 of output VAT.
• Purchase of software and licenses: €5,000 + 23% VAT = €1,150 of input VAT.
• Office rent: €3,000 + 23% VAT = €690 of input VAT.

The VAT calculation for the 2nd quarter is: €13,800 - (€1,150 + €690) = €11,960. The company will have to submit the DP-IVA by August 20, 2026, and pay the €11,960 by August 25, 2026.

Common Errors in the Quarterly Regime

A common mistake is cash flow management. As the payment is more spaced out, companies may not adequately provision for the VAT amount to be paid, facing liquidity difficulties when the deadline arrives. Another failure is not monitoring turnover. If a company on the quarterly regime exceeds the €650,000 limit during the year, it is obliged to switch to the monthly regime in the following year, a change that must be communicated to the AT in a timely manner.

Other Relevant Annual and Periodic Obligations

In addition to CIT and VAT, a company's tax calendar is filled with other equally important obligations, which concern assets, inventories, and payments to non-resident entities.

Inventory Communication

Companies with organized accounting that are required to prepare an inventory must communicate to the AT the value of their stocks as of December 31 of the previous year. This communication is done through a specific file, the format of which is defined by the AT. The inventory communication, mandatory for taxpayers with organized accounting, must be done by January 31, even if there are no stocks. The obligation remains even for service companies that, by nature, do not have inventory; in these cases, the communication must be made by declaring the absence of stocks. Failure to comply with this communication is subject to fines under the RGIT.

Municipal Property Tax (IMI) and Additional to IMI (AIMI)

IMI is a municipal tax levied on the Taxable Asset Value (VPT) of real estate. The rates are set annually by each municipality. The payment is phased according to the amount:

• Up to €100: Single payment in May.
• Between €100 and €500: Two installments, in May and November.
• Over €500: Three installments, in May, August, and November.

For companies holding real estate with a total VPT exceeding €600,000, the Additional to IMI (AIMI) applies. The rate for legal entities is 0.4% on the sum of the VPTs, with assessment and payment in September.

Practical Case: IMI Payment

A factory owns an industrial pavilion with a VPT of €800,000. The municipality's IMI rate is 0.4%. The annual IMI to be paid is €800,000 * 0.4% = €3,200. As the amount is over €500, it will be paid in three installments of approximately €1,066.67 in May, August, and November 2026.

Model 30 Declaration - Income Paid to Non-Residents

Whenever a Portuguese company pays income to a non-resident entity (interest, royalties, dividends, services), it is generally required to withhold tax at source. The Model 30 Declaration is used to declare these payments and the withholdings made. Model 30 is mandatory for payments to non-residents and must be submitted by the end of the second month following the payment, according to Article 128 of the CIRS and 119 of the CIRC. For example, paying for a service to a Spanish company in June 2026 requires the submission of Model 30 by August 31, 2026.

The Strategic Role of the Certified Accountant

In such a dense and dynamic tax landscape, the figure of the Certified Accountant (CC) transcends that of a mere executor of obligations. The CC is an indispensable strategic partner for the health and growth of any company. Their involvement is not limited to filling out and submitting returns; it encompasses advice, planning, and tax optimization.

Ensuring Compliance and Mitigating Risks

The primary function of the CC is to ensure that the company complies with all its tax and social security obligations within the legal deadlines. The signature of a Certified Accountant is mandatory for the submission of the Model 22 Declaration and the IES, ensuring the reliability of the financial and tax information. This technical responsibility, shared with the company's management body, provides a seal of quality and reliability to the information reported to the AT. A qualified CC is permanently updated on legislative changes, interpreting and applying them to the specific reality of each client, thus mitigating the risk of fines, compensatory interest, and tax inspection proceedings. The choice of an experienced accounting partner is, therefore, a critical management decision. For more information on how to choose the right service, you can consult the options available in accounting service packages.

Tax Planning and Optimization

Beyond compliance, a proactive CC acts as a financial and tax consultant. Through a rigorous analysis of the company's activity and results, the CC can identify optimization opportunities. This includes:

• Management of Payments on Account: Advising on the possibility of suspending the third CIT PPC, improving the company's liquidity.
• Leveraging Tax Benefits: Identifying eligibility and supporting applications for regimes such as RFAI (Tax Incentive for Investment) or SIFIDE II (System of Tax Incentives for Corporate R&D).
• Structuring Operations: Advising on the most tax-efficient way to carry out certain operations, such as corporate restructuring or acquisitions.
• Analysis of Deductible Expenses: Guiding management on which expenses are fiscally accepted, avoiding negative adjustments to taxable profit.

Continuous and transparent collaboration between the company's management and its Certified Accountant transforms accounting from an obligation into a value-creation tool.

Summary of the Annual Tax Calendar (Checklist for 2026)

To facilitate visualization and planning, here is a simplified checklist with the main tax obligations throughout the year for a typical company in Portugal.

Monthly Obligations

• By the 5th: Communication of the SAF-T (PT) file for the previous month's invoicing.
• By the 10th: Submission of the Monthly Remuneration Statement (DMR) for the previous month.
• By the 20th: Payment of Social Security contributions and withheld IRS (related to the DMR).
• By the 20th: Submission of the Periodic VAT Return (monthly regime) for the second preceding month.
• By the 25th: Payment of VAT (monthly regime) for the second preceding month.

Quarterly Obligations (Quarterly VAT Regime)

• By May 20: Submission of the 1st Quarter VAT return. (Payment by May 25)
• By August 20: Submission of the 2nd Quarter VAT return. (Payment by August 25)
• By November 20: Submission of the 3rd Quarter VAT return. (Payment by November 25)
• By February 20 (following year): Submission of the 4th Quarter VAT return. (Payment by February 25)

Annual and Ad-hoc Obligations

• January (by the 31st): Communication of Inventories valued as of December 31 of the previous year.
• End of the registration month: Payment of the Single Circulation Tax (IUC).
• May (by the 31st): Submission of the Model 22 CIT return for the previous year and payment of the tax.
• May: Payment of the 1st installment of IMI or full payment.
• July (by the 15th): Submission of the Simplified Business Information (IES) for the previous year.
• July (by the 31st): Payment of the 1st Payment on Account (or Additional) for CIT.
• August: Payment of the 2nd installment of IMI.
• September (by the 30th): Payment of the 2nd Payment on Account (or Additional) for CIT.
• September: Payment of the Additional to IMI (AIMI), if applicable.
• November: Payment of the 3rd installment of IMI.
• December (by the 15th): Payment of the 3rd Payment on Account (or Additional) for CIT.

This calendar is an essential tool, but its practical application may vary depending on the specifics of each company, such as its tax regime or the existence of specific tax benefits like the IFICI regime in Madeira. Regular consultation with an accounting professional is the safest way to ensure full compliance.

Sources and Legal References

• Corporate Income Tax Code (CIRC) - Approved by Decree-Law No. 442-B/88, of November 30.
• Value Added Tax Code (CIVA) - Approved by Decree-Law No. 394-B/84, of December 26.
• Personal Income Tax Code (CIRS) - Approved by Decree-Law No. 442-A/88, of November 30.
• General Regime of Tax Infractions (RGIT) - Approved by Law No. 15/2001, of June 5.
• Decree-Law No. 198/2012, of August 24 - Establishes control measures for the issuance of invoices and other fiscally relevant documents, including the SAF-T communication obligation.
• Decree-Law No. 8/2007, of January 19 - Creates the Simplified Business Information (IES).
• Ordinance No. 60/2013, of February 18 - Approves the Monthly Remuneration Statement (DMR).
• Municipal Property Tax Code (CIMI) - Approved by Decree-Law No. 287/2003, of November 12.