CAE Codes in Portugal: How to Choose the Right Activity Code

• Art. 151.º CIRS classifies an IRS taxpayer's activity by the CAE or by the codes in a ministerial table (Portaria 1011/2001). They are alternatives, not two steps.
• CAE-Rev.4 has applied since 1 January 2025 (Decreto-Lei 9/2025) and replaced Rev.3. Some AT help pages still say Rev.3, so check the current code before you file.
• The nature of your income sets your IRS coefficient (art. 31.º): 0.75 for professions specifically listed in the art. 151.º table, 0.35 for other services, 0.15 for sales of goods.
• It also sets your Social Security rate: 21.4% for services, 25.2% for sole traders with commercial or industrial income.
• The code alone does not decide VAT: turnover and the exemption rules do. Some professions, such as doctors and psychologists, are exempt by nature (art. 9.º CIVA).

When you open atividade, the AT asks for the code of the activity you will carry out. You can take it from the CAE, the national classification (now Revisão 4), or from the profession table behind art. 151.º of the IRS Code. This applies if you will invoice as a sole trader or freelancer. Next: write down what a client actually pays you for, find it in both lists, and declare the code that fits. It is not a formality, because the activity feeds your IRS coefficient and can change your Social Security rate.

Two lists, one purpose

Art. 151.º CIRS is one sentence long: the activities of IRS taxpayers are classified, for IRS purposes, according to the CAE of the Instituto Nacional de Estatística, or according to the codes in a table of activities approved by ministerial order. The AT's leaflet on starting an activity names that table: Portaria n.º 1011/2001, of 21 August. So the CAE and the art. 151.º table are two ways of naming the same thing. The pack of advice you may have read that treats CAE as the list for businesses and the CIRS table as the list for professions is not what the law says.

The AT's start-of-activity page adds a third list to the questionnaire: «atividades de elevado valor acrescentado». That is the list behind the high-value-added incentive regimes, which our NHR and IFICI guide covers. If you are not claiming one of those regimes, it is not your list.

One rule from the AT's own FAQ is worth knowing: a company can have only a CAE code, never a CIRS code. Individuals with professional income who take up a different activity from the one they declared must change their CIRS code. The AT leaflet adds the mechanism. Moving to a different activity is a declaração de alterações, not a cessation.

CAE Rev.4: what changed

Decreto-Lei n.º 9/2025, of 12 February, establishes CAE-Rev.4. Its art. 8.º says it takes effect on 1 January 2025, and its art. 7.º repeals Decreto-Lei 381/2007, the diploma behind Rev.3. Under art. 2.º the code you declare is the fifth level, a five-digit subclass. INE manages the classification and publishes equivalence tables between Rev.3 and Rev.4 (arts. 4.º and 5.º). The AT's own leaflet now names CAE-Rev.4 as the list to use.

Why it matters in practice: numbers moved and meanings moved. In the Rev.4 annex, programação informática is 62100 and consultoria em informática is 62201, while 47910 is now «atividades de serviços de intermediação no comércio a retalho não especializado». A code copied from a blog post or an old invoice written before 2025 has to be checked against the current list, not assumed. Some AT help pages, such as the CAE FAQ, still say Rev.3, so do not treat a page's silence as confirmation.

How to choose the code

1. 1
   Write down what the client pays you for

   «Digital services» is too vague. «UX design for a client's software product» or «online language tutoring» is specific enough to search for.

2. 2
   Check the art. 151.º table for a listed profession

   The 0.75 coefficient applies to activities «specifically provided for» in that table, so it matters whether your work is actually listed there, not what the label sounds like.

3. 3
   Search the current CAE Rev.4 descriptions

   Use INE's classification search and read the full Rev.4 subclass notes, including exclusions, not only its title. Check an older code against the equivalence tables before using it.

4. 4
   Declare every activity you will really carry out

   The AT asks for the «código(s) de atividade». If you will do genuinely different work, declare each. Do not add codes «just in case».

5. 5
   Check the consequences separately

   IRS, Social Security and VAT each follow their own rules. The next section shows what the activity does and does not decide.

Teachers and tutors: which CIRS code?

If you personally teach or tutor as a self-employed professional, start with the named professions in the official article 151 table. These are four-digit CIRS codes, not five-digit CAE codes:

Example: describe private maths tutoring as tutoring, not simply ‘education’. Running a school or training business needs its own activity analysis; do not apply a personal teaching code to a company, which can only register CAE codes. If the description overlaps, ask INE about the CAE classification and AT about the tax registration.

Is 1519 a CAE code, and does it mean less tax?

1519 is the CIRS entry ‘Outros prestadores de serviços’, not a CAE subclass. It does not itself name a specific profession. AT Circular 2/2016, points 4–5 explains the distinction; the current article 31 still separates specifically listed professional services (0.75) from other services (0.35). Registering 1519 does not turn teaching, programming or another specifically listed profession into an unlisted service. Classify the real work first; do not select the label to obtain a coefficient.

Look up, check or change a code

• Choosing a new CAE? Follow INE's official lookup instructions: SMI → Classificações → Versões → search ‘CAE Rev.4’. Read the explanatory notes and exclusions; use ‘Correspondência de versões’ to compare an old code.
• Checking what you already registered? The AT FAQ 4405 points to ‘Posição Integrada’ on Portal das Finanças. SICAE is the public company/equivalent-entity register, not a complete directory of individuals' CIRS codes.
• Adding or changing an individual's activity? Use ATividade → Submeter declarações → Alteração de Atividade, not a new initial declaration. Review the codes and effective dates, submit only once correct and recheck the registered activity afterwards. A saved draft is not a submitted amendment. Companies may first need an IRN change if the new activity is outside their corporate object.
• Preparing the declaration? Use the activity-registration walkthrough; the finder suggests candidates but does not register or change anything for you.

What your activity decides

IRS. Under the simplified regime, taxable income is your turnover times a coefficient set by art. 31.º n.º 1 CIRS:

Example: €20,000 of service income in a normal year gives €15,000 of taxable income at 0.75 and €7,000 at 0.35, before the deductions and expense check in art. 31.º n.os 2 and 13. The gap is the reason to declare what you actually do, and the law asks about the activity, not the label on it. In the year you start and the next, the 0.75 and 0.35 coefficients are cut by 50% and 25%, so 0.375 and 0.5625 for a listed profession, as long as you have no employment or pension income in those years and did not close another activity less than five years ago (art. 31.º n.os 10 and 11). The 0.15 coefficient is not reduced.

Social Security. Sole traders with commercial or industrial income under art. 3.º n.º 1 a) CIRS are «empresários em nome individual» (art. 134.º n.º 1 b) of the Código Contributivo) and pay 25.2%. Workers providing services under art. 3.º n.º 1 b) pay 21.4% (art. 168.º n.os 1 and 4). So an activity registered on the commerce side changes the rate, and our guide to how contributions are calculated explains the rest of the maths.

VAT. The AT frames you in an IVA regime from what the declaration says, including your estimated turnover, not from the code alone. Some professions are exempt by their nature: art. 9.º CIVA exempts services by doctors, dentists, psychologists, nurses and paramedical professions. For everyone else the exemption turns on turnover and conditions, which our IVA guide for freelancers and the IVA threshold checker cover.

What to have ready before you file

• The code or codes of the activity you will carry out, from the art. 151.º list or the CAE-Rev.4.
• Your estimated turnover for the rest of the current year, not for twelve months. If you will also do VAT-exempt work under art. 9.º, count only the taxable part.
• An IBAN and BIC/SWIFT for a bank account in your own name.
• If you are a comerciante em nome individual, your registration at the Conservatória: the declaration is due within 15 days of it, and always before you start.

Common mistakes

• Using a pre-2025 code without checking it against Rev.4. The same number can now describe something else.
• Choosing a code for the coefficient it seems to give. The law asks whether the activity is specifically listed, so the real work is what counts.
• Not filing a declaração de alterações when the activity changes. The AT treats a switch to a different activity as an amendment, not a closure.
• Assuming the code does not matter for Social Security. Commercial and service activities sit on different rates.
• Copying another freelancer's code when your service is different.