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Autoridade Tributária e Aduaneira (AT): Guide for Businesses

By Rauva

Published on 13 November 2023

7mins read

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Welcome to our guide on the Autoridade Tributária e Aduaneira (AT) for small business in Portugal. Navigating the intricacies of tax and customs in a new country can be daunting. This guide aims to demystify the AT, making your journey as a business owner smoother and more compliant with Portuguese regulations.

The AT, under the Ministry of Finance, plays a pivotal role in administering taxes, customs duties, and other levies. It ensures compliance with tax obligations, combats tax fraud, and represents the public treasury in judicial bodies. For a new business, understanding and engaging with the AT is not just a legal necessity; it's a step towards financial clarity and operational efficiency.

Whether you're starting a business, managing your taxes, or expanding your operations, this guide will serve as your compass. We'll walk you through online services, in-person support options, and common operations that are particularly relevant to small businesses. Our aim is to provide you with the knowledge and resources to navigate the AT's systems with confidence and ease.

What is the Autoridade Tributária e Aduaneira?

The Autoridade Tributária e Aduaneira (AT), a key arm of Portugal's Ministry of Finance, is integral to the country's financial and economic framework. AT's mission is multifaceted, focusing on the administration of taxes, customs duties, and other related levies. Its activities are crucial for maintaining the financial health of the state and supporting societal protections.

For small businesses, understanding the role of AT is vital. Here's what AT does:

  • **Tax Assessment and Collection:** AT is responsible for ensuring the proper calculation and collection of taxes. This includes a range of taxes such as income tax (IRS), corporate tax, and VAT, among others.
  • **Tax Inspection and Fraud Prevention:** Vigilance against tax evasion and fraud is a cornerstone of AT's responsibilities. They employ various measures to prevent and counteract these activities, ensuring a fair and lawful tax environment.
  • **Tax Justice and Representation:** AT also plays a role in the judicial arena, representing public treasury interests and ensuring adherence to tax laws.
  • **Information and Assistance:** Perhaps most importantly for new businesses, AT offers guidance and support in tax-related matters. They provide information to help businesses understand and meet their tax obligations.

The AT's activities are not just about enforcement; they are about creating an environment where businesses can thrive within the bounds of legal and financial compliance. As a new business owner, engaging with AT effectively means you are setting up your venture on a solid, compliant foundation.

Online Services at the Autoridade Tributária e Aduaneira

In today's digital age, the Autoridade Tributária e Aduaneira (AT) has embraced technology to facilitate easier access to its services. For small business owners, the AT's online portal, Portal das Finanças, is a vital resource. This platform allows you to manage various tax-related tasks efficiently and conveniently from your computer or smartphone.

Here’s a breakdown of key online services that are particularly useful for small businesses:

  • **IRS Declarations and Consultation:** You can submit and consult your income tax declarations directly through the portal.
  • **NIF Issuance:** Obtaining a Número de Identificação Fiscal (NIF) for individuals is a straightforward process online, essential for any business activity in Portugal.
  • **VAT Declarations and Fiscal Debt Consultations:** Manage VAT-related matters and keep track of any fiscal debts.
  • **IUC Payments:** The portal also allows for the payment and consultation of the Unique Circulation Tax (IUC).

These online services not only save time but also provide a level of clarity and control over your fiscal responsibilities. They are designed to be user-friendly, even for those new to Portugal's tax system. Utilizing these services effectively can lead to better financial management and compliance with Portuguese tax laws.

For a comprehensive understanding of all the services offered and how to navigate them, visiting the Portal das Finanças is highly recommended. It's an invaluable tool for managing your business's tax affairs with ease and confidence.

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e-balcão and Telephonic Support

Understanding and managing tax obligations can sometimes require direct assistance. The Autoridade Tributária e Aduaneira (AT) provides two invaluable support channels: e-balcão and telephonic support.

  • **e-balcão:** This online helpdesk is accessible via the Portal das Finanças. It is a convenient way to seek information or clarifications on tax payments, inquiries about charges and refunds, and specific tax issues like IMI, IRS, or VAT. The e-balcão is designed to be user-friendly, offering prompt responses to your queries.
  • **Centro de Atendimento Telefónico (CAT):** For those who prefer speaking to a representative, AT's telephone support centre is available. The CAT team assists with questions regarding taxes, customs duties, and helps with navigating the Portal das Finanças services. You can reach CAT at 217 206 707, available on weekdays from 9 am to 7 pm. Remember to have your tax identification number or access code handy for efficient service.

These support options underscore AT's commitment to assisting small business owners. Whether you have a simple query or need detailed guidance, these channels offer reliable and professional support to ensure your tax matters are handled correctly.

In-Person Services

While the online services of the Autoridade Tributária e Aduaneira (AT) are comprehensive, there are times when in-person assistance is necessary or preferred. AT offers several options for face-to-face services:

  • **Finance Counters and Lojas de Cidadão:** AT services are available at various finance counters and select Lojas de Cidadão (Citizen Shops) throughout Portugal. These locations can handle a range of tax-related services. To find out if a particular Loja de Cidadão has a finance counter, you can visit their website.
  • **Scheduling Appointments:** To avoid waiting times and ensure a more efficient service, you can schedule an appointment at a finance counter. This can be done through the Portal das Finanças or by calling the Centro de Atendimento Telefónico (CAT). Scheduling is particularly recommended for services related to the Número de Identificação Fiscal (NIF) or other tax-specific queries.

In-person services are a great way to get direct assistance, especially for complex queries or when initiating certain tax-related activities. The staff at these locations are trained to offer guidance and support, ensuring that your business complies with Portuguese tax regulations.

Common Operations for Small Businesses

For small business owners in Portugal, familiarising themselves with common operations at the Autoridade Tributária e Aduaneira (AT) is key to efficient business management. Here are some of the most relevant operations:

  • **IRS (Income Tax) Consultation and Submission:** Keeping up with income tax obligations is crucial. AT's online portal simplifies this process.
  • **IMI (Municipal Property Tax) Verification and Payment:** Understanding and managing property taxes is essential for businesses owning real estate.
  • **Obtaining Property Registration Documents:** Accessing property-related documents like the caderneta predial is important for real estate transactions.
  • **IUC (Vehicle Tax) Payment and Consultation:** If your business involves vehicles, managing IUC is a necessary part of operations.
  • **VAT Declarations:** Efficient management of VAT, both in terms of declarations and payments, is key for businesses dealing with goods and services.

Each of these operations plays a part in the smooth functioning of your business and compliance with Portuguese tax law. Leveraging AT's resources to understand and manage these aspects can lead to a more streamlined and successful business operation.


Navigating the Autoridade Tributária e Aduaneira (AT) is a critical aspect of running a small business in Portugal. This guide has provided you with an overview of AT's roles, online services, support options, in-person assistance, and common operations relevant to your business. By understanding and utilising these resources, you set the foundation for compliant and efficient business management.

We encourage you to explore the Portal das Finanças and other AT services further. With the right knowledge and tools, managing your business's fiscal responsibilities can be straightforward and less intimidating. Remember, staying informed and proactive about your tax obligations is key to your business's success in Portugal.

FAQ: Autoridade Tributária for Small Businesses

How do I register my new business with the Autoridade Tributária?

You can register your business online through the Portal das Finanças. The process involves obtaining a Número de Identificação Fiscal (NIF) and declaring your business activity.

What are the key tax obligations for small businesses in Portugal?

Key obligations include submitting IRS (income tax), paying IMI (property tax) if applicable, managing VAT obligations, and IUC (vehicle tax) for business-related vehicles.

Can I handle my tax submissions online?

Yes, the Portal das Finanças allows you to submit tax declarations, like IRS and VAT, online. You can also consult and manage fiscal debts through the portal.

Where can I get assistance if I have questions about my taxes?

AT offers support through the e-balcão service on the Portal das Finanças and telephonic support through the Centro de Atendimento Telefónico (CAT). For more complex queries, in-person assistance is available at finance counters and some Lojas de Cidadão.

Is it possible to schedule an appointment for in-person services?

Yes, you can schedule appointments for in-person services at finance counters through the Portal das Finanças or by contacting CAT.

How do I ensure my business complies with Portuguese tax laws?

Staying informed about your tax obligations and utilizing AT's resources, like the Portal das Finanças and support services, will help ensure compliance. Regularly consulting official resources and seeking professional advice when needed is advisable.

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Written by Rauva

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