The deadline for submitting the Q1 2026 quarterly VAT return is 20 May 2026, while the payment of the assessed tax must be made by 25 May 2026. These dates apply to taxable persons under the normal quarterly regime with a turnover of less than €650,000, as per the VAT Code.

By Hugo Velez Ribeiro, Certified Accountant (OCC nº 64356) · 14/05/2026

Introduction to Quarterly VAT Framework in 2026: A Comprehensive Overview

As we approach the end of the first economic quarter, businesses and self-employed professionals in Portugal must prepare for one of the most critical reporting obligations in the tax calendar. Compliance with the Q1 2026 quarterly VAT deadline is not merely an administrative requirement but a fundamental pillar of treasury management and tax compliance. To successfully navigate these waters, it is essential to rely on professional accounting services that ensure accuracy in tax assessment, avoiding contingencies and optimising the tax burden.

In Portugal in 2026, the standard VAT rate remains at 23% on the mainland, applying to most supplies of goods and services. In the Autonomous Regions of Madeira and the Azores, reduced rates apply, specifically 22% and 16% for the standard rate, respectively, as per Regional Legislative Decree No. 2/2007/M and Regional Legislative Decree No. 1/2008/A. This indirect tax requires the taxable person to act as a fiduciary of the State, collecting the amount from the final customer for subsequent remittance to public coffers. Accuracy in completing the Periodic VAT Return (DPIVA), as provided for in Article 29 of the VAT Code (CIVA), avoids heavy fines and unnecessary tax inspections, ensuring transparency and legality of operations.

Managing quarterly VAT is a complex process involving the correct classification of operations, the application of appropriate rates, the deduction of input VAT, and strict adherence to legal deadlines. This article aims to provide an exhaustive guide for Q1 2026, covering everything from critical deadlines to deductibility rules, common errors to avoid, and practical examples illustrating the application of legislation.

Deadlines and Tax Calendar for Q1 2026: Submission and Payment

Declarative compliance adheres to strict calendar rules, which are crucial to avoid penalties. According to the changes introduced in recent years, notably by Decree-Law No. 85/2022, of 21 December, which amended the deadline for submitting the periodic VAT return, the submission deadline and the payment deadline have been staggered. This measure aims to allow for better liquidity management by companies and more effective tax planning.

The deadline for submitting the periodic VAT return for Q1 2026 (January to March) is 20 May 2026. The return must be submitted electronically through the Tax Portal, as per Article 29, No. 1, paragraph c) of the CIVA. This submission is mandatory for all taxable persons under the normal quarterly regime, i.e., those whose turnover in the previous calendar year did not exceed €650,000.

After submission, the taxpayer has an additional period to settle the payment slip. The payment of the VAT assessed in Q1 2026 must be made by 25 May 2026, as provided for in Article 27, No. 1, paragraph b) of the CIVA. It is essential to note that if these days coincide with weekends or holidays, the deadline shifts to the next business day. However, in 2026, these dates are critical to avoid late payment interest and fines for late payment of the tax liability.

Submission vs. Payment: Essential Distinction

Many business owners, especially those starting their activity, confuse the submission of the return with the payment of the tax. Submission is the act of sending the XML file or filling out the form on the Tax Portal with the values of Output VAT (resulting from sales and services) and Input VAT (related to the acquisition of goods and services). This process is a formal declaration to the Tax and Customs Authority (AT) about the operations carried out in the quarter.

Payment, on the other hand, is the actual transfer of funds to the State's coffers, corresponding to the assessed and due tax. Under Article 27 of the CIVA, the tax must be remitted to authorised collection points (banks or ATMs, using the payment reference generated on the Tax Portal) within the established deadlines. Failure in any of these steps, whether submission or payment, entails legal and financial consequences.

Deductibility Rules and Exemptions in 2026: Tax Optimisation

One of the most complex and, at the same time, most important aspects of VAT is determining what can or cannot be deducted. The correct application of deduction rules allows for optimising the company's cash flow and avoiding undue payments. Not all invoices received grant the right to deduction, even if they are related to professional activity. Limitations on the right to deduction are expressly provided for in Article 21 of the CIVA.

The right to deduct VAT on entertainment expenses and fuel (petrol) is limited to 0% in Portugal in 2026, except for exceptions provided for in Article 21 of the CIVA. For example, input VAT on entertainment expenses is, as a rule, totally excluded from the right to deduction. In the case of fuels, the general rule is non-deductibility for petrol, while for diesel and LPG, the deduction is generally 50%, with some exceptions for public transport vehicles, goods vehicles, or machinery, where the deduction can be 100%.

For VAT to be deductible, the expense must be strictly necessary for obtaining taxable income and fall within the categories defined by Article 19 of the CIVA. Expenses with diesel, for example, generally allow a 50% deduction, while expenses with electricity for electric vehicles can reach 100% deduction, promoting energy transition and sustainability. It is crucial that the invoice contains all mandatory elements, namely the purchaser's NIF (tax identification number), and that the VAT is duly itemised.

Practical Example of Assessment and Deductions

Consider an IT consulting company, under the normal quarterly VAT regime. In Q1 2026, it invoiced €20,000.00 + VAT (23%). The Output VAT was €4,600.00. In the same period, it had the following expenses:

• Acquisition of servers: €5,000.00 + VAT (23%), resulting in €1,150.00 of Input VAT.
• Office rent: €1,000.00 + VAT (23%), resulting in €230.00 of Input VAT.
• Acquisition of diesel for a commercial vehicle: €200.00 + VAT (23%), resulting in €46.00 of VAT. With a 50% deduction, the deductible VAT is €23.00.
• Business lunches (entertainment expenses): €100.00 + VAT (23%), resulting in €23.00 of VAT. This amount is not deductible.

The total Input VAT would be: €1,150.00 (servers) + €230.00 (rent) + €23.00 (diesel) = €1,403.00.

The amount to be paid to the State by 25 May 2026 would be €3,197.00 (€4,600.00 - €1,403.00). This example highlights the importance of detailed accounting records and the correct application of deductibility rules to avoid excessive payments or future corrections by the AT.

VAT Exemptions: Article 53 and Others

In addition to deductibility rules, it is essential to understand VAT exemptions. The most common exemption for small businesses is that provided for in Article 53 of the CIVA, which exempts from tax taxable persons who do not have organised accounting and who, in the previous calendar year, had a turnover of less than €15,000 (value for 2026, subject to legislative changes). It is crucial to emphasise that, although exempt from VAT, these taxable persons still have tax obligations, such as issuing invoices with the mention "VAT - Exemption Regime - Art. 53 of the CIVA" and submitting the declaration of commencement/alteration of activity.

There are other specific exemptions, such as those relating to certain public interest operations (medical services, education, culture), financial and real estate operations, and intra-Community operations or exports, which must be analysed on a case-by-case basis and duly justified, as per Articles 9, 14, and 15 of the CIVA.

Invoicing and Series Communication Obligations: Transparency and Control

VAT compliance begins with invoice issuance. The invoice is the basic document for tax assessment and for exercising the right to deduction. In 2026, the use of software certified by the Tax Authority (AT) is mandatory for almost all economic operators, except for rare exceptions provided for in Ordinance No. 363/2010, of 23 June. This obligation aims to ensure the integrity and immutability of invoicing data.

Furthermore, the ATCUD code and QR Code must be included on all invoices issued in Portugal in 2026. The ATCUD (Unique Document Code) is a validation code that allows for the unique identification of each tax document, while the QR Code facilitates the communication of invoices by consumers. These measures, introduced by Decree-Law No. 28/2019, of 15 February, strengthen tax control and combat fraud and evasion.

The communication of invoice elements must be made by the 5th day of the month following issuance, through the submission of the SAFT-PT file or direct communication on the Tax Portal. If a company fails this monthly communication, data cross-referencing in the quarterly return will generate divergence alerts, potentially leading to inspection actions. Under Article 3 of Decree-Law No. 198/2012, of 24 August, which establishes the rules for invoice communication, omission or delay in communicating invoices can result in fines that vary depending on the size of the company and the seriousness of the infraction.

Common Errors to Avoid in Quarterly VAT: Contingency Prevention

The complexity of VAT legislation and the multiplicity of operations can lead to frequent errors which, in turn, result in fines and late payment interest. Knowing and avoiding these errors is fundamental for efficient and smooth tax management.

1. Confusing Exemption Regime with Quarterly Regime: Many new entrepreneurs think that because they are exempt under Article 53 of the CIVA, they do not have to submit returns. However, if the annual turnover exceeds the €15,000 limit, the taxable person must change their framework to the normal regime (monthly or quarterly) through an alteration declaration, under penalty of being retroactively taxed and paying fines.
2. Improper Deduction of VAT on Ineligible Expenses: Except for rare exceptions (such as the organisation of congresses, fairs, exhibitions or seminars, as per Article 21, No. 2, paragraph c) of the CIVA), VAT on meals, accommodation and business travel is not deductible. The same applies to entertainment expenses, tobacco and alcoholic beverages. The improper deduction of these amounts is one of the most common errors and easily detectable by the AT.
3. Forgetting Reverse Charge VAT: For services acquired from abroad (e.g., Facebook or Google ads, software, consulting), the Portuguese taxpayer must self-assess VAT in Portugal, filling in fields 16 and 17 (intra-Community acquisitions of services) or 18 and 19 (other operations with reverse charge) of the return. Omission of this self-assessment leads to an under-declaration of tax, subject to correction and penalties.
4. Not validating E-Fatura and invoice communication: Failure to confirm invoices on the E-Fatura portal before the end of the quarter or the absence of communication of sales invoices within the legal deadline makes it impossible to automatically deduct certain expenses (for final consumers) and can generate discrepancies in AT data, respectively. It is crucial to ensure that all sales invoices are communicated and that relevant purchase invoices are validated.
5. Delay in Submitting the Return or in Payment: Even a small delay can result in fines and late payment interest. The minimum fine for late submission of the DPIVA is €150.00, and can reach €3,750.00, as per Article 27 of the General Regime of Tax Infractions (RGIT). In the case of late payment, late payment interest and fines are added, which can vary between 30% and 100% of the outstanding tax.
6. Error in Applying VAT Rates: Selling products or services with incorrect VAT rates (e.g., applying the standard rate to a product that benefits from a reduced rate) can lead to overpayment (loss for the company) or underpayment (debt to the AT). It is essential to know the rates applicable to each good or service, especially when dealing with products subject to differentiated rates.
7. Failure to make necessary rectifications: If errors or omissions are detected in already submitted returns, it is essential to rectify them. Article 78 of the CIVA and Article 140 of the Tax Procedure and Process Code (CPPT) allow for the submission of substitute returns, with specific deadlines and conditions that must be observed to avoid penalties.

Detailed Case Studies: Application of Legislation in Practice

Scenario A: Service Provider with Intra-Community Acquirers

A graphic designer in Portugal, a VAT taxable person under the normal regime, provides web development services to a company in Germany for €10,000. The German company is also a VAT taxable person registered for intra-Community VAT purposes (it has a valid intra-Community NIF, verified in VIES).

As this is an intra-Community supply of services between two taxable persons, the reverse charge rule applies, as per Article 6, No. 6, paragraph a) of the CIVA. The place of supply of services is that of the acquirer, i.e., Germany.

The designer issues the invoice without VAT, obligatorily mentioning "VAT – Reverse Charge [Article 6, No. 6, paragraph a) of the CIVA]" and the acquirer's intra-Community NIF. In the Q1 2026 periodic VAT return, this amount of €10,000 must be declared in field 7 ("Supplies of goods and services located in other Member States"). In addition, the designer will have to submit the Recapitulative Statement (model 30), identifying the intra-Community operation. This operation does not generate tax payable in Portugal.

Scenario B: Trade of Goods with Differentiated Rates and Adjustments

A grocery store in Portugal, under the normal quarterly regime, sells products with reduced (6%), intermediate (13%), and standard (23%) rates. In Q1 2026, its sales were:

• €5,000 at 6% = €300 Output VAT (field 1 of the DPIVA).
• €2,000 at 13% = €260 Output VAT (field 3 of the DPIVA).
• €1,000 at 23% = €230 Output VAT (field 5 of the DPIVA).

Total Output VAT: €300 + €260 + €230 = €790.

In the same period, it had the following purchases:

• Purchases of product stock at 6%: €4,000 + VAT (6%) = €240 Input VAT.
• Purchases of office supplies at 23%: €100 + VAT (23%) = €23 Input VAT.

Total Input VAT: €240 + €23 = €263.

The net amount payable would be €527 (€790 - €263). This amount would be entered in field 95 of the DPIVA. It is vital to correctly separate the taxable bases by rate in fields 1, 3, and 5 of the DPIVA and the deductible VAT in fields 20, 21, and 22 (according to the type of goods and services). Furthermore, if the grocery store received a credit note from a supplier for €50 + VAT (23%) in the quarter, this VAT amount (€11.50) would be an adjustment in favour of the taxable person, to be included in field 41 of the DPIVA, reducing the VAT payable.

Step-by-Step: How to Proceed for Q1 2026 Effectively

To ensure smooth tax compliance, it is essential to follow a set of organised and timely steps:

1. Claim and Verification of Invoices: By the end of April, ensure that all suppliers have issued the invoices corresponding to your acquisitions and that these are listed on the E-Fatura Portal (for taxpayers who validate expenses). Check the conformity of invoices (NIF, address, description, itemised VAT). Any missing or incorrect invoice should be promptly requested or corrected.
2. Detailed Accounting Assessment: Gather and classify all sales and purchase documents for the quarter (January, February, March). Accurately assess Output VAT and Input VAT, taking into account applicable rates and deductibility rules. Check for any credit notes to be processed (Article 78 of the CIVA) or other adjustments affecting the tax. It is advisable to use certified accounting software to automate this process and minimise errors.
3. Completion of the Periodic VAT Return (DPIVA): Access the Tax Portal > Submit > VAT > Periodic Return. Fill in all relevant fields of the return, with special attention to Output VAT fields (fields 1 to 6), Input VAT fields (fields 20 to 24), and adjustment fields (fields 40 to 44) and intra-Community operations fields (fields 7 to 10 and 16 to 19).
4. Validation and Early Submission: Use the validation functionality available on the Tax Portal to detect logical errors or inconsistencies before final submission. This is a crucial step to avoid rejections or the need for substitute returns. Submit the return with some anticipation of the 20 May deadline, avoiding system congestion or last-minute unforeseen events.
5. Generation and Payment of the VAT Slip: After submission, the system automatically generates the payment slip (Doc. Model P2). Obtain the payment reference and schedule the bank transfer or make the payment through authorised channels (ATM, home banking) so that it occurs strictly by 25 May 2026. Always keep proof of payment.
6. Document Archiving: Keep all supporting documentation (invoices, receipts, bank statements, payment proofs) duly organised and archived for a minimum period of 10 years, as per Article 52 of the CIVA and Article 123 of the Corporate Income Tax Code (CIRC), for inspection purposes.

Conclusion and Final Recommendations: The Importance of Proactivity

VAT management requires rigour, planning, and in-depth knowledge of tax legislation. Failure to comply with the Q1 2026 quarterly VAT deadline, whether in submitting the return or paying the tax, can result in minimum fines of €150.00, plus late payment interest, and in more serious cases, tax enforcement proceedings. Proactivity is, therefore, the best strategy.

We strongly recommend never leaving the submission until the last day, preventing failures in the Tax Authority's system or unexpected technical problems. It is advisable that the assessment and submission of the return be done with a safety margin of a few days before the deadlines.

For optimised management and to ensure that you take advantage of all legal tax benefits and deductions, minimising risks and maximising tax efficiency, collaboration with a Certified Accountant is indispensable. A qualified professional can offer specialised advice, ensure the correct application of tax rules, and represent the company before the Tax Authority.

Consult our complete guide to accounting for businesses for more information on how our services can help your organisation stay compliant and thrive in the Portuguese tax environment.

Sources and Legal References

• Value Added Tax Code (CIVA): Articles 6 (place of supply of services), 9 (exemptions), 14 (exemptions in intra-Community operations), 15 (exemptions in exports), 19 (right to deduction), 21 (exclusions from the right to deduction), 27 (payment deadline), 29 (returns), 52 (document retention period), 53 (exemption for small retailers), 78 (adjustments).
• Decree-Law No. 198/2012, of 24 August: Establishes the rules for communicating invoices to the Tax Authority.
• Decree-Law No. 85/2022, of 21 December: Amendment of tax submission and payment deadlines, introducing the staggering between submission and payment.
• Ordinance No. 363/2010, of 23 June: Regulates the conditions for using certified invoicing software.
• Regional Legislative Decree No. 2/2007/M, of 24 January: Establishes VAT rates in the Autonomous Region of Madeira.
• Regional Legislative Decree No. 1/2008/A, of 11 January: Establishes VAT rates in the Autonomous Region of the Azores.
• General Regime of Tax Infractions (RGIT): Article 27 (fines for declaration-related infractions).
• Tax Procedure and Process Code (CPPT): Article 140 (substitute returns).