Disclaimer: This article provides general information about Portuguese tax and compliance rules and does not constitute tax, legal or accounting advice. Individual circumstances vary and rules change. Always consult a qualified Portuguese accountant or contabilista certificado before making decisions based on this information.
“Do I have to pay for invoicing software?” is one of the most asked and worst answered questions in Portuguese freelancing. The usual answer is “only above €50,000”, which is true as far as it goes and leaves out the condition that catches most people.
At Remote Work Europe we see this one land in the inbox every few weeks, usually from somebody who has just been quoted a monthly subscription they are not convinced they need. Often they are right. Sometimes they are very wrong, and for a reason nothing to do with how much they earn.
Certified software is mandatory if any one of three things is true. Not all three. Any one.
When is certified invoicing software mandatory in Portugal?
You must use invoicing software certified by the tax authority if:
a) Your turnover last calendar year was over €50,000 – or, in the year you start out, your annualised turnover for that period exceeds it.
b) You use invoicing software at all.
c) You are required to keep organised accounting, or you have opted for it.
⚠️ The conditions are not cumulative. The tax authority states this explicitly: it is enough that one of them applies.
Why does using any invoicing software trigger the requirement?
Read it again, because it is circular in a way that trips almost everyone up.
If you choose to use invoicing software, that software must be certified. There is no tier of “informal” invoicing apps for small freelancers. You cannot pick up a generic invoicing tool, or a foreign SaaS product that produces tidy PDFs, and rely on being under €50,000 to justify it.
Being below the turnover threshold does not give you free choice of tool. It gives you the option not to use software at all.
What can I use instead of certified software?
The law allows invoices to be processed in three ways: by invoicing software, by other electronic means such as cash registers and electronic terminals, or by pre-printed documents from an authorised printer.
If none of the three conditions applies to you, you have real choices within that.
AT’s own invoicing applications. Since 1 July 2025 the tax authority’s own invoicing tools are an express statutory alternative, under a provision added specifically to allow it: notwithstanding the certified-software obligation, you may use AT’s applications.
⚠️ That carve-out matters more than it looks. AT’s applications are themselves invoicing software, so without it, condition (b) would arguably drag you straight back into the certification requirement for using them. The provision exists precisely to stop that circle closing. For a freelancer issuing a handful of invoices a month, this is usually the answer.
Pre-printed documents from an authorised printer. Still lawful. Old-fashioned, but it is a real option and the printer handles the compliance codes.
⚠️ And if you do use certified software, keep the paper route in mind: when the software is unavailable, you are required to issue pre-printed documents from an authorised printer and recover them into the system afterwards.
Do I need an ATCUD on my invoices?
The ATCUD – the unique document code – is required on all invoices and other fiscally relevant documents, regardless of your turnover or tax regime. This is not a large-business obligation. All VAT taxable persons are covered, whether their activity is taxed or exempt.
“Fiscally relevant documents” is broader than people expect: invoices, simplified invoices, faturas-recibo, credit and debit notes, receipts, transport documents, and any other document that could be shown to a client to check goods or services – whatever it is called.
⚠️ You obtain an ATCUD by communicating your document series to AT and receiving a validation code, per document type and processing method. That can be done manually through the Portal das Finanças or by webservice.
✅ If you issue through the Portal das Finanças, this is automatic. The series is communicated for you, the validation code is assigned, and the ATCUD is included in the document. Nothing to configure.
Do I need a QR code on my invoices?
Here the rule is narrower than most guidance suggests.
The QR code is required only on documents issued by AT-certified invoicing software. If you are issuing through the Portal or by other permitted electronic means, there is no QR obligation.
Where both appear on a certified-software document, the ATCUD on the page carrying the QR code must sit immediately above it, and both must be clearly legible however the document is presented.
Which rules apply to me? A quick reference
| Your situation | What you need |
|---|---|
| Turnover under €50,000, no organised accounting, issuing through the Portal | Portal is enough. ATCUD automatic, no QR needed |
| Turnover under €50,000, but you want to use an invoicing app | ⚠️ The app must be certified |
| Turnover over €50,000 | Certified software, ATCUD and QR |
| Organised accounting, whatever your turnover | Certified software, ATCUD and QR |
| Opted into organised accounting | Certified software from the date you opt in |
What should I plan for as my turnover grows?
Crossing €50,000 changes your obligations from the following year, so it is worth watching in the same way you watch the IVA thresholds. If your work is growing, the decision to move onto certified software is one you can make calmly in advance or badly in a hurry.
Choosing organised accounting triggers it immediately, regardless of turnover – from the date you exercise the option.
⚠️ AT publishes the list of certified programs and their approved versions. If you are choosing a tool, check it against that list rather than the vendor’s marketing. “Compliant with Portuguese requirements” on a website is not the same as appearing on AT’s list.
Portugal invoicing software rules: the short version
- Any one of the three conditions makes certified software mandatory
- Using invoicing software at all is one of those conditions – being small does not let you pick any tool
- ATCUD applies to everyone, and is automatic through the Portal
- QR codes apply only to certified software
- Since July 2025, AT’s own invoicing applications are a lawful alternative – for many freelancers, the simplest answer
The wider rhythm of what you file and when is in our Portugal freelancer compliance calendar, and if your clients are abroad, what goes on the invoice is a separate question again.
