Quick answer
No, not all companies are required to use certified invoicing software — but most businesses that already issue invoices on a computer are, in practice, covered by the obligation. AT VAT taxpayers who:
have their registered office, permanent establishment or domicile in Portugal (or are registered for VAT purposes in Portugal); and
have had, in the previous year, a turnover exceeding €50,000; or
use computer billing programs (even with reduced turnover); or
are required to have organized accounting or have opted for it.
If you do not meet any of these criteria and continue to invoice only through invoice books printed at an authorized printer or directly on the Finance Portal, you may not be legally obliged to have your own invoicing program — but it is important to always confirm your specific case with your accountant. legislative:
VAT Code (CIVA), in particular articles 29, 36 and 40, which define the obligation to issue invoices;
Decree-Law no. No. 363/2010, of 23 June, which establishes the certification regime for computer invoicing programs.
Decree-Law no. processed by one of the following means:
invoicing computer programs (including the invoicing application provided by AT);
other electronic means, such as cash registers or terminals electronic;
pre-printed documents in an authorized typography.
For many taxpayers, the law goes further: when they meet certain criteria, they cannot freely choose between these means and are forced to use exclusively invoicing programs certificates.
Who is required to use certified invoicing software?
Article 4 of Decree-Law no. 28/2019 establishes the so-called obligation to use specific means. In practical terms, this means that certain taxable persons are no longer able to issue manual invoices or use non-certified programs and will now have to use an invoicing program certified by AT.
In this situation, IRS or IRC taxable persons who:
had, in the previous calendar year, a turnover greater than 50,000 €; or
use computer invoicing programs to issue invoices or other fiscally relevant documents; or
are required to have organized accounting or have opted for that form of accounting.
These conditions are alternatives: it is enough for one of them to occur for there to be an obligation to use certified software. In many cases, there are, in fact, several at the same time (for example, a limited liability company with organized accounting and turnover exceeding €50,000).
The obligation applies not only to companies and entrepreneurs with their registered office or permanent establishment in Portugal, but also to non-resident taxable persons who are registered for VAT purposes in Portugal and issue invoices in accordance with domestic legislation.
Summary
Business situation Is certified software mandatory? Company with organized accounting (IRC) Yes. It is mandatory to use a certified invoicing program.
Independent worker with organized accounting (IRS) Yes. It is mandatory to use a certified invoicing program.
Company or professional with turnover > €50,000/year Yes. Even if you previously used manual invoices.
Business that already uses any computer program to invoice Yes. The program must be certified by AT.
Professional under a simplified regime, General rule, no. You may not be required to have your own software, but you must confirm this on a case-by-case basis.
Who may not be required to use certified software?
The law does not make a direct list of “exemptions”, but, by excluding parts, it is possible to identify some situations in which the use of certified software may not be mandatory.
Typically, may not be required:
Small businesses and independent professionals under a VAT exemption regime or simplified regime, with an annual turnover of less than €50,000, without organized accounting, who issue invoices only through books printed in an authorized typography or from the Portal das Finance.
Very specific activities that resort to the isolated act issued directly on the Finance Portal.
Some specific entities covered by their own regimes (for example, certain small retailers that use only register machines), as long as none of the above mandatory conditions are met.
However, there is a critical point: if these taxpayers decide, on their own initiative, to start using an invoicing program, that program must be certified. In other words, from the moment they opt for software, they will no longer be able to use Excel sheets or “homemade” applications.
Given the complexity of particular situations (CAE, VAT framework, type of clients, etc.), it is highly recommended to always validate the framework with a certified accountant before making a definitive decision.
What it is not permitted to
Issue invoices in Excel, Word or “homemade” applications when you are obliged to use certified software. These files are not considered certified billing programs and may lead to fines.
Switching between certified software and manuals arbitrarily. If you are obliged to use a certified invoicing program (for example, because you have organized accounting), the rule is that all fiscally relevant documents are issued through that program. invoices.
The Order of Certified Accountants itself has reiterated that the use of non-certified programs, when the law requires certified software, may have relevant consequences, including the non-acceptance of expenses and the imposition of fines significant.
What are the fines for not using certified software when it is mandatory?
The General Regime of Tax Infractions (RGIT) provides for specific fines for the lack of use of certified billing programs or equipment, when legally required.
In indicative terms, the failure to use certified invoicing programs can be punished with a fine which, depending on the severity and specific situation, can reach amounts in the order of several thousand euros, approaching, in the most serious cases, 18 750 €.
In addition of the fine, non-compliance may have other impacts:
rejection of expenses for IRC or IRS purposes of the issuer or customers;
greater likelihood of inspections and corrections unofficial;
loss of credibility with customers and partners.
Why does the State require certified invoicing software?
The requirement for certified programs does not exist just to “complicate life” to companies. The main objective is to ensure that invoices and fiscally relevant documents meet requirements of:
integrity — cannot be easily altered once issued;
authenticity — is possible identify who issued them;
tracking and auditing — all records are stored in a way that allows supervision;
standardized data export, namely through the file SAF‑T (PT).
In addition to the tax perspective, a well-designed certified invoicing program brings operational advantages to the business itself: it automates tax calculations, facilitates reporting, simplifies communication with the accountant and reduces the risk of errors.
What you should do in the practice
Confirm your status: check with your accountant the turnover, the VAT regime and whether or not you are required to have organized accounting.
Define the means of invoicing: if you meet any of the legal criteria, you must opt for a certified invoicing program. If you are not already obliged, consider whether it makes sense to anticipate the transition to software, due to the gains in control and image.
Choose a program certified by AT: the list of certified programs is available on the Finance Portal. Always confirm the AT certification number and whether the program supports QR code, ATCUD, SAF‑T (PT) and electronic communication with AT.
Implement good practices: create well-defined billing series, communicate them to AT, keep users and permissions under control and make backups
Work together with the accountant: involve your accountant in choosing and configuring the software to ensure that all information is handled correctly.
If you are starting a business or modernizing your invoicing process, cloud solutions designed for the Portuguese context, such as SimpleSum, help you stay focused on the business while ensuring compliance with legal requirements.
Quick questions frequent
I am self-employed on a simplified basis, below €50,000 per year. Do I really have to use certified software?
It depends. If you do not have organized accounting and only issue invoices through the Finance Portal or invoice books printed from an authorized printing press, you may not be covered by the legal obligation to use your own invoicing program. However, if you decide to start invoicing using a computer program, that program will have to be certified by AT.
Can I continue to issue invoices in Word or Excel?
No. Invoices in Word, Excel or other editable files do not constitute a certified invoicing program. If it is covered by any of the mandatory conditions (turnover, organized accounting or simple option for software), the use of this type of files may be considered a tax offense.
Does the Finance Portal count as certified software?
Yes. The application for issuing invoices and receipt invoices available on the Finance Portal is a means of invoicing provided by AT itself and complies with legal requirements. Still, for larger volume businesses or more advanced management needs, a dedicated certified invoicing program is generally more efficient.
If I start using a certified program, can I keep some customers with manual invoicing?
The rule is that once you are covered by the obligation to use a certified invoicing program, all fiscally relevant documents must be issued through this program. Systematically mixing different invoicing methods may raise doubts upon future inspection.
This content is for informational purposes only and does not exempt you from consulting applicable legislation, updated guidelines from the Tax and Customs Authority, or professional advice from a certified accountant.