Opening an AL activity in Portugal: CAE codes, Tax Portal, and the mistakes that cost you later

When you decide to move forward with alojamento local, there's a sequence of administrative steps you need to complete before welcoming your first guest. One of the most critical — and most often done badly — is registering your activity on the Tax Portal (Portal das Finanças) with the correct CAE code.

It's not complicated, but it does require attention. The wrong code, or an activity opened after the fact, can create tax problems that only surface months later — by which point you already have bookings, income, and a backlog of reporting obligations.

What "opening an activity" means and why it's mandatory

Whenever you start earning income on a regular basis — including AL income — you're required to notify the Tax Authority (Autoridade Tributária, AT). That notification is called opening an activity (abertura de atividade) and it's done through the Portal das Finanças.

Without it, any income you receive sits in a fiscal grey zone: undeclared, uncategorised, and potentially subject to retroactive corrections with interest.

The general rule is that the activity must be opened before you start invoicing. Not after the first booking, not when you get around to it — before.

The CAE code: getting it right from the start

The Código de Atividade Económica (CAE) identifies the type of activity you carry out. For alojamento local, there are specific codes within the tourist accommodation division — and the right choice depends on your property type and the specific AL modality you're registering under.

The most common mistake is picking a generic code, or one that doesn't match your registered modality (villa, apartment, guest house, room). It might seem like a minor detail, but it has real consequences: your tax treatment, VAT obligations, and even how the AT interprets your activity all flow from the CAE you declare.

What you should do:

• Check the official CAE list on the INE portal or the current Portuguese Classification of Economic Activities — don't rely on third-party lists or articles that may be out of date.
• Confirm which code corresponds to your specific AL modality.
• If in doubt, contact the AT directly or speak to a certified accountant (contabilista certificado) before submitting anything.

Don't go from memory on this one — verify at the source before filling in any form.

How to open your activity on the Portal das Finanças

The process is done online, authenticated with your NIF and password or Chave Móvel Digital. The general path is:

1. Go to the Portal das Finanças (portaldasfinancas.gov.pt)
2. Navigate to Serviços → Entregar → Início/Alteração de Atividade
3. Fill in the details: CAE, activity start date, VAT regime, and IRS regime
4. Submit and save your confirmation receipt

That confirmation document matters — keep it alongside the rest of your AL paperwork.

VAT regime: don't assume you're exempt

When opening your activity, you'll need to declare your VAT regime. Many AL hosts with turnover below a certain threshold qualify for the VAT exemption set out in the Portuguese VAT Code — but the threshold and the applicable conditions need to be confirmed with an accountant, because they depend on your projected turnover and the exact nature of your activity.

Don't automatically assume you're exempt. Confirm it.

The most common mistakes — and how to avoid them

1. Opening the activity after you've already received income

This happens more often than you'd think: the host registers the property, starts taking bookings, and only then deals with the tax side. The AT can take the view that the activity should have been opened earlier and apply corrections accordingly.

How to avoid it: handle the activity registration before you publish your listing — or at the very latest, before you receive any payment.

2. Choosing the wrong CAE

We've covered this already, but it's worth repeating: the CAE field is not one to fill in quickly. Once submitted, it can be changed, but that requires filing an activity amendment — more paperwork, more risk of inconsistencies in your records.

3. Not keeping the confirmation receipt

It sounds obvious, but many hosts can't locate this document when they need it — during an inspection, a financing application, or when switching accountants.

How to avoid it: create a dedicated digital (or physical) folder for your AL from day one. Activity registration receipt, municipal registration, AL number, insurance policy — all in one place, all accessible.

4. Confusing the tax registration with the municipal registration

Opening your activity with the AT is one thing. Registering your alojamento local with the Câmara Municipal — which generates your AL number — is another. These are separate processes, with separate bodies, and both are mandatory.

Many hosts complete one and forget the other, or do them in the wrong order.

Documentation: the habit that saves you headaches

One of the clearest patterns that separates hosts who stay on top of compliance from those who are constantly firefighting is simple: they document everything from the start.

You don't need a sophisticated system. Just a centralised location — a cloud folder, a physical folder, whatever works for you — where you keep:

• Activity registration receipt (AT)
• AL registration number (Câmara Municipal)
• Multi-risk insurance policy
• Correspondence with the AT or municipality
• Invoices and receipts issued

When it comes time to file declarations, respond to a notification, or simply get your bearings, having everything in one place is worth far more than it sounds.

In summary

Opening your AL activity isn't the hardest step in the process — but it's one of the ones with the most consequences if done badly. Choose the right CAE (verify at the source), open the activity before you invoice, keep the confirmation receipt, and don't confuse the tax registration with the municipal registration.

If you have any doubts about the correct setup for your specific situation, a certified accountant is always the safest route before submitting any declaration.