Between opening your activity and closing it, there’s a step in the middle many people forget: when something changes in your activity - where you work, the type of work, the IBAN, the VAT regime - you have to tell the Tax Authority. It’s called the change-of-activity declaration (declaração de alterações), and it has a short deadline. This guide tells you what and how.
What triggers a change declaration
Whenever one of the details on your activity-opening declaration changes, you have to update it. The most common cases for a freelancer:
The deadline: 15 days
The general rule is clear: you have 15 days from the date the change happened to report it (unless the law sets another deadline for a specific case). It’s not something to “leave for the IRS” - it’s an obligation with its own deadline.
How to do it
Careful: a VAT regime change has its own calendar nuances (when you cross into or out of the art. 53.º exemption, the effect and the deadline depend on when you cross the threshold). If that’s your case, confirm the dates - it can be a costly mistake in this declaration. For the other changes described here, the 15-day rule applies as a rule.
✅ In summary
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The change declaration reports to the Tax Authority the changes in your open activity - place of activity, CAE, VAT regime, IBAN. It’s the middle piece, between opening and closing an activity.
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As a rule, you have 15 days from the change to file it, online on the Portal das Finanças (or in person) - but a VAT-regime change has its own calendar (see above). The address can be updated via the Citizen Card, which reports it on its own.
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With FIZ you keep your activity data organised and know when a change (like crossing the VAT threshold) means you have to act - without missing the deadline. See the plans.
