Tax Authority (Finanças)Automatic collection

Proof of Change of Activity (Comprovativo de Alteração de Atividade)

Proof of the declaration of changes submitted to the AT when you change your activity code, tax regime or other registration details.

What it is for

Show your accountant or a client that your tax registration has been changed.
Compare the start-of-activity declaration with the changes made afterwards.
Confirm which details were reported to the AT with each change.

Example (fictitious). Titus Gorila starts offering training courses in addition to consultancy. He keeps the proof of change to justify the new code to his accountant.

What it is

This document proves the declaration by which you informed the AT of a change to an activity you had already registered. The change may concern CAE or CIRS codes, your tax regime or other details. It identifies what was changed; it does not record a new registration.

How we collect it

We request it using the holder's NIF and Tax Portal (Portal das Finanças) password. We deliver the official PDF of the proof.

Access required: Tax Portal (Portal das Finanças). Credentials are encrypted only during the collection and deleted at the end.

Things to note

A tax change is neither a professional licence nor proof of income, and it only reflects the situation at the time of the declaration. If you are asked for your current IVA regime, check whether the specific certificate is needed instead.

Frequently asked questions

Is changing my activity the same as registering a new one?

No. A change updates the details of an activity that is already registered; the registration itself is proven by the proof of start of activity.

Does the most recent proof I have reflect my current situation?

Not always, as there may have been later changes. Check the history and the date before submitting it.