FIZ is a Portuguese app that invoices, files VAT and Social Security and will submit your Modelo 3 for a fee. Finkavo prepares your Modelo 3 and files it with the AT once you confirm; VAT and Social Security you still file yourself. Here is which job each does.
Join the waitlistWhat this page says about FIZ was read from fiz.co on 21 September 2026, including the prices. We re-read it at least every quarter. We have no commercial relationship with FIZ and receive no referral fee.
If you want another service to submit your VAT and Social Security for you too, FIZ does that and Finkavo does not. Its pages say it imports your data from the AT, files for you, and pays fines on declarations it submits, up to a stated limit. Finkavo is for understanding the law, working out the numbers and preparing the Modelo 3, which it files with the AT only after you confirm.
It files. Its IRS page says it imports your income, withholdings and deductions from the AT, walks you through what is missing, and submits the Modelo 3 for you, or gives you the XML to upload yourself. Beyond IRS it issues certified invoices and files VAT and the quarterly Social Security declaration. It also offers a fines guarantee it calls Tax Shield and an AI tax consultant that answers questions by chat or WhatsApp.
Its IRS page lists Anexos A, B, E, F, J and L and says Portuguese-source capital gains and pensions are not covered at the time of reading. It is built for independent professionals and sole traders, and says its base plan is not for companies.
Use Finkavo to understand the rule, check a figure, work out capital gains or foreign tax credits, and prepare the Modelo 3, which it files with the AT once you confirm. It offers no fines guarantee. Some people use both: FIZ to file, Finkavo to check the answer.
| FIZ | Finkavo | |
|---|---|---|
| What it is | An app and website for independent professionals in Portugal: certified invoicing, VAT and Social Security declarations, IRS filing, an AI tax consultant, and Tax Shield. | An assistant for tax and admin in Portugal: cited answers, calculators, guides, deadline tracking and letter triage. It prepares the Modelo 3 and files it once you confirm. |
| The Modelo 3 | Its IRS page says it imports your data and deductions from the AT, you add what is missing, and FIZ files, or you download the XML and submit yourself. It lists Anexos A, B, E, F, J and L. | Finkavo helps you prepare and understand the return, with capital-gains and foreign-income calculators. You file on the Portal das Finanças. |
| Price | FIZ's IRS page shows €49.99 per filing (fiz.co, read 21 September 2026). Its plans page shows, for VAT-exempt sole traders, FIZ Base at €0, FIZ Auto at €9.99 and FIZ Prime at €14.99 a month. | Free calculators and guides. Paid plans are priced per year or per letter, and are on our pricing page. |
| Fines guarantee | Its home page says Tax Shield pays fines on declarations submitted through FIZ, up to €500 on Auto and €1,500 on Prime (fiz.co, read 21 September 2026). | Finkavo offers no fines guarantee. |
| Your Portal access | To file directly, its FAQ says FIZ logs in to the Portal das Finanças with your NIF and password, which it says is encrypted and can be deleted on request. Entering data by hand is the alternative. | Finkavo's preparation pack is built from what you enter or import. It files the Modelo 3 only after you confirm, or you upload it yourself. |
| Best for | You want someone else to submit, and your income fits the anexos it lists. | You want the rule explained with sources, or income FIZ does not list, or a second check on a return. |
Do you want another service to submit your Modelo 3 for you?
Its IRS page says it does, either by logging in to the Portal das Finanças with your credentials or by giving you the XML to upload yourself (fiz.co, read 21 September 2026).
No. Finkavo prepares and explains, and you submit on the Portal das Finanças.
No. We have no commercial relationship with FIZ and receive no referral fee. If that ever changes, this page will say so.
The ones fiz.co showed on 21 September 2026. Prices change, so check its plans page before you decide.
