Descodify vs doing nothing
AT doesn't forget. It just takes a while.
Many solo entrepreneurs in Portugal assume that if nothing bad has happened yet, they're fine. No letter from AT, no penalty, no problem. But the Portuguese tax authority works on its own timeline. And when it catches up, it catches up with interest.
Invoicing, coming soon
Get early access - free tier includes unlimited invoicing.
A real example: €95 in bank interest, 4 years later
Our founder received an email from AT in early 2026 about income earned in 2022. Not a huge amount - €95.30 in bank interest from Sweden, €106.17 from Germany, and salary from a Swedish company. AT had exact figures, provided by the Swedish and German tax authorities through automatic EU information sharing.
The income was from before his Portuguese tax residency - correctly excluded from his IRS declaration. But AT didn't know that. They gave him 15 days to file a corrected declaration or explain why. Finding proof from a German bank account closed 4 years earlier meant digging through moving boxes from 2022.
What happens when you skip obligations
These aren't theoretical risks. They're what AT does.
Missed VAT declaration
Fine of €150–3,750 per missed quarterly declaration. AT may also estimate your VAT liability and charge interest on the amount. They don't send reminders - the deadline passes and the clock starts.
Late or missing IRS filing
Fine of €150–3,750 if filed late. If you don't file at all, AT can issue an estimated assessment and charge you tax on presumed income - which is usually higher than what you actually earned.
Undeclared foreign income
EU countries share financial data automatically through the Common Reporting Standard. Bank interest, dividends, employment income - AT will eventually know about it. The delay can be years, but the data arrives.
Skipped e-fatura review
If you don't review and categorize your e-fatura expenses by Feb 25, some may be incorrectly categorized or not counted toward your deductions at all. You lose deductions you were entitled to - and pay more tax than necessary.
Not tracking the 15% proof requirement
Under the simplified regime, falling short of the 15% expense proof threshold means your taxable income increases. You find out when you file your IRS - too late to do anything about it for that year.
No proof when AT asks for it
AT can request documentation for any of the last 4 years. If you can't produce bank statements, contracts, or receipts to support what you filed (or didn't file), AT defaults to the interpretation that costs you the most.
The cost of catching up
€150–3,750
per missed declaration
Each missed VAT, IRS, or SS filing carries its own fine. They add up.
4% per year
compensatory interest
Interest on unpaid tax runs from the original due date. Not from when AT notices.
Hours
of paperwork
Gathering proof years after the fact. Correcting declarations. Responding to AT within 15-day deadlines.
A few minutes
per month
What it actually takes to stay on top of your obligations when you have the right tool.
Don't wait for the email from AT
Start with free invoicing and the obligation calendar. See every deadline, know every number, and keep your proof organized - so when AT comes asking, you're ready.
Invoicing, coming soon
Get early access - free tier includes unlimited invoicing.