Descodify vs waiting until tax season
By June, five deadlines have already passed.
The Modelo 3 submission window opens April 1 and closes June 30. That's when most people think about their IRS. But by then the decisions that affect your tax bill - household composition, expense categorization, deduction confirmation - already happened. In February and March.
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The IRS cycle nobody told you about
Filing your IRS isn't a single event in June. It's a year-round cycle with distinct phases - and missing the early ones costs you money.
Year-end prep
Gather documents: foreign bank statements, invoicing records, tax returns from other countries. If you wait until June, you'll be scrambling for paperwork from 6+ months ago.
Agregado familiar - deadline Feb 15
Confirm or update your household composition on AT. Got married? Had a child? Divorced? This is the window. Miss it and AT uses last year's data - which could mean filing jointly when you shouldn't, or missing a dependent deduction.
If you wait until June, this is already locked in.
e-Fatura review - deadline Feb 25
Review and categorize every invoice linked to your NIF. Some expenses need manual categorization - the system couldn't tell if that pharmacy purchase was health or cosmetics. Miss this and expenses may count toward the wrong deduction category or not count at all.
Incorrectly categorized expenses = lost deductions.
Deduction confirmation - deadline Mar 31
AT pre-fills your Anexo H deductions based on e-fatura data. Review them: health, education, housing, general family expenses - each with a maximum cap. If the numbers are wrong, this is your last chance to contest.
By April, these deductions are final.
Filing period - Apr 1 to Jun 30
If you handled the three phases before this, filing is mostly reviewing what's already been calculated. Household confirmed, expenses categorized, deductions verified. You're confirming choices you already made - not starting from scratch.
This is the easy part. If you prepared.
What waiting actually costs
Lost deductions
Expenses you didn't categorize during the e-fatura window may default to the wrong category or not count toward any deduction. Every purchase where you skipped your NIF is a deduction that was never created.
Wrong household data
If your life changed in 2025 (marriage, children, separation) and you missed the Feb 15 deadline, AT files you based on last year's situation. You could be paying more tax or missing entitled benefits.
Panic and mistakes
Rushing through your IRS in the last week of June, searching for documents you should have gathered in January, guessing at numbers you should have confirmed in March. Mistakes in IRS filings lead to AT divergências - and those come with their own deadlines and documentation requirements.
No proof when AT asks
AT can request documentation for the last 4 years. If you didn't store proof alongside your filing, finding bank statements and receipts years later is painful - sometimes impossible. Just ask our founder about his German bank statements from 2022.
Descodify tracks the whole cycle
Not just the filing in June. Every phase: January prep, February household and e-fatura deadlines, March deductions, and the filing itself. You see where you are in the cycle, what's due next, and what you need to do about it. Deadlines don't slip by because you forgot they existed.
Start before tax season
The best time to start was January. The second best time is now. Upload your previous declarations, see what was filed, and be ready for the next deadline.
Invoicing, coming soon
Get early access - free tier includes unlimited invoicing.