Crypto Tax Documentation & Modelo 3 Reporting in Portugal

Once you understand how PT taxes your crypto (capital gain vs Cat B income), you still need to actually file it. This is the practical mechanics: which Anexo, which Quadro, what fields - and the documentation that has to sit behind every line you enter. Filing window is April 1 to June 30, 2026 for 2025 income.

What documentation do you need for crypto taxes in Portugal?

For every disposal you declare, the Modelo 3 forms ask for the same six data points: the acquisition date and EUR value, the disposal date and EUR proceeds, the fees on both ends, the NIF and country of the exchange or custodian (entidade gestora), and the country of the counterparty. That is the exact column set of both Anexo G Quadro 18A (taxable, under 365 days) and Anexo G1 Quadro 7 (exempt, 365 days or more). If your records can produce those six per disposal, filing is transcription; if they can’t, you’ll be reconstructing history in June.

The full set worth keeping:

Record	Why you need it
Full transaction CSV export + annual statement from every exchange	The per-disposal dates, EUR values and fees the forms ask for
Wallet history for self-custody assets	Acquisition dates and cost basis for anything not on an exchange
Wallet-to-wallet self-transfer trail	Proves a transfer was not a disposal, so your 365-day clock and basis survive the move
EUR valuation evidence	The exchange’s reported EUR price at the time, or an ECB reference-rate conversion you can show
The original acquisition behind every swap chain	Swaps aren’t taxable and basis carries through - but at the fiat exit you must show the original date and cost
Fee receipts	Despesas e encargos: only costs “necessary and actually incurred” on acquisition and disposal count
For gifted or inherited crypto: the Modelo 1 do Imposto do Selo or proof of stamp-duty payment	Fixes your acquisition value for a later sale, and a Portuguese custodian needs it to release the assets

One ordering rule shapes all of this: CIRS art. 43.º deems the crypto you dispose of to be the oldest you hold - FIFO - applied per custodian when your assets sit at more than one institution or platform. So keep acquisition history per exchange and per wallet, not just a blended portfolio view: which units count as sold, and whether they cross the 365-day line, depends on it.

How long do you have to keep crypto records?

The statutory answer is four years after the year the documents relate to (CIRS art. 128.º), and when AT asks you have 15 days to produce them (extendable to 25 if you show they’re hard to obtain).

The practical answer is longer: keep acquisition records for as long as you hold the asset, plus four years after the year you dispose of it. The acquisition date is what proves the 365-day exemption, and holding periods started before the regime existed still count - the transition rule in Lei n.º 24-D/2022 (art. 220.º) counts time held before 1 January 2023 toward the 365 days. A coin bought in 2017 and sold in 2026 is exempt precisely because of a 2017 record.

What if you’re missing acquisition records?

You’re not automatically stuck. Art. 128.º itself says that when documents are lost for reasons beyond your control, the facts can be proven by any adequate alternative evidence. In practice, reconstruct from:

• Exchange data exports - most platforms let you download full history back to account opening; EU platforms must hand over your data on request under GDPR even for closed accounts
• Bank statements - your fiat on-ramps and off-ramps date and size every EUR movement into and out of crypto
• The blockchain itself - explorers give timestamps and amounts for on-chain acquisitions and transfers; pair them with a historical EUR price source
• Old confirmation emails - trade and withdrawal confirmations are contemporaneous evidence of dates and amounts

Two warnings. If an exchange you used is shutting down or has collapsed, download your history now - reconstruction gets dramatically harder once the portal goes dark. And if AT considers your declared values diverge from reality, it can substitute its own determination, presuming the disposal value to be market value at the disposal date (CIRS art. 52.º) - weak documentation doesn’t just risk a penalty, it hands AT the valuation pen.

Before you start

Have the documentation set above ready, plus your Portal das Finanças login (password or Chave Móvel Digital).

Pulling the records together by hand across multiple exchanges and wallets is the painful part. A crypto tax tool like Koinly connects to your exchanges and wallets, applies FIFO, converts everything to EUR, and exports a per-disposal summary you can transcribe straight onto Anexo G. Affiliate link — TAXCLARA earns a commission if you subscribe through it, at no extra cost to you; we only link tools we’d use ourselves.

Anexo G: capital gains from disposals

Anexo G is for Cat G income - disposals where you received something other than crypto in return, typically a sale into euros. Each disposal is one line in the table.

Quadro 18 - crypto-asset transactions (the dedicated table)

This is the table added in 2023 specifically for crypto. There is no field for the token symbol or the number of units - AT works entirely from dates and euro amounts. Required fields per disposal:

Field	What goes here
Titular	Which household member held the asset
Entidade Gestora	NIF and country of the exchange or custodian
Realização (ano/mês/dia, valor)	Disposal date and EUR proceeds
Aquisição (ano/mês/dia, valor)	Acquisition date and EUR cost basis
Despesas e encargos	Fees directly tied to the acquisition and disposal
País da contraparte	Country of residence of the buyer

Long-term holds (365+ days): file Anexo G1, Quadro 7

Exempt is not the same as undeclared. Gains and losses on crypto held 365 days or more are excluded from taxation by CIRS art. 10 - but the disposal itself is still declared, on Anexo G1 (“Mais-valias não tributadas”), whose Quadro 7 exists specifically for “criptoativos que não constituam valores mobiliários detidos por período superior ou igual a 365 dias”. The AT’s own criptoativos leaflet points exempt disposals there. The fields mirror Quadro 18A: custodian NIF and country, realisation date and value, acquisition date and value, expenses, counterparty country. No tax results from any of it - the annex reports untaxed gains, and your acquisition date on the form is what evidences the 365-day holding.

The same Quadro 7 also covers the deemed disposal that happens when you lose Portuguese tax residence while holding long-term crypto.

Quadro 18A on Anexo G stays limited on its face to crypto “detidos por um período inferior a 365 dias” - short-term disposals only. Long-term goes on G1, short-term on G, and nothing goes nowhere.

Short-term holds (under 365 days)

The 28% flat rate applies by default. If you want englobamento (aggregate with other income at progressive brackets), tick the Quadro 15 box marked “Optar pelo englobamento” (Option for aggregation).

Use the crypto tax calculator to decide whether englobamento or flat 28% is cheaper for your total income mix.

Losses

Net losses for the year can offset net gains. Excess losses carry forward 5 years - but only if you opt for englobamento. CIRS art. 55 allows the carry-forward “quando o sujeito passivo opte ou seja obrigado a englobar esses rendimentos”, so if you stay on the flat 28% you lose the unused losses. The carry-forward must be claimed on each future return; AT doesn’t auto-track it.

The non-EU counterparty rule (Quadro 18B)

The 365-day exemption has an override that catches people using offshore venues. Under Quadro 18B, a disposal is taxable regardless of how long you held it when one of the parties is resident outside the EU/EEA and there is no double-tax convention or exchange-of-information agreement with that country. Most major jurisdictions (US, UK, Singapore) are covered by an agreement and so fall outside this, but genuinely offshore counterparties do not. Check before assuming a multi-year hold is exempt.

Losing PT tax residence also triggers a deemed disposal of your holdings, which is the other way the 365-day exemption stops applying.

Yield: mining, staking, lending

Start with the category, because it decides whether you file Anexo B at all.

Category E is the default for passive yield

CIRS art. 5 puts “quaisquer formas de remuneração decorrentes de operações relativas a criptoativos” - staking rewards, lending interest, DeFi yield - in Category E, taxed at 28%. You only land in Category B if you’re carrying this on as a business.

There’s a big carve-out: where the reward is itself paid in crypto, art. 5 defers taxation entirely. Nothing is taxed on receipt; the reward is taxed as a capital gain when you eventually dispose of the coins you received. That covers most ordinary staking. Filing those rewards as Cat B revenue means opening an activity, paying Social Security and paying tax years early on income that isn’t yet taxable.

If you are genuinely in Category B

Register the activity and file Anexo B. Two things people get wrong:

• The activity code goes in Quadro 3A, campo 07 (the Tabela do art. 151.º code plus its CAE) - not Quadro 5, which is the option to be taxed under Category A rules.
• There is no coefficient-selection quadro. The coefficient follows from which field of Quadro 4A you use: campo 419 for crypto operations generally, which carries a coefficient of 0.15 (15% taxable), and campo 422 for mining, which carries 0.95. Quadro 17 is Despesas e encargos.

That split is the single most valuable number in this guide. Campo 419 taxes you on 15% of gross; campo 422, which is mining and nothing else, taxes you on 95%. Putting the wrong campo on the form multiplies your taxable base by more than six.

Social Security

Your contribution base is 70% of relevant Cat B income, and you pay 21.4% of that base monthly, on figures set by your quarterly declaration. The first 12 months from opening the activity are exempt. Gross income and contracting entities are reported to Segurança Social on the Anexo SS filed with your Modelo 3.

Anexo J: foreign-source crypto income

If your crypto exchange is non-PT (Coinbase US, Binance Global, Kraken EU outside PT, Bitstamp, etc.), the disposals technically have foreign source. The 2026 conservative position:

• Long-term holds (365+ days) disposed at gain: Anexo G1, Quadro 7, same as domestic - the exclusion applies wherever the exchange sits, and the quadro’s entidade gestora columns take a country code for a foreign platform
• Short-term holds disposed at gain: Anexo J, Quadro 9.4A, which mirrors Anexo G Quadro 18A field for field
• Foreign capital income (Cat E yield paid in fiat): Anexo J, Quadro 8

AT settled the Anexo G vs Anexo J question in the form itself: Anexo J carries a dedicated Quadro 9.4 - Alienação onerosa de criptoativos que não constituam valores mobiliários for disposals obtained outside Portuguese territory. Use Quadro 18 for domestic, Quadro 9.4 for foreign.

If your origin country (US, UK, etc.) withheld tax on the disposal, claim foreign tax credit on Anexo J. The PT-US tax treaty caps double-taxation; you can credit foreign tax paid against your PT liability up to the PT rate.

Anexo L: NHR / IFICI status

If you’re under NHR or IFICI, file Anexo L declaring qualifying activity income. Crypto disposals generally do not qualify - the 365-day Cat G exemption already gives you 0% on long-term holds, so there’s nothing to claim under NHR.

Mining and staking income doesn’t generally qualify for NHR’s 10% pension treatment or IFICI’s 20% qualifying activity rate either - it’s taxed under the normal Category E or Category B rules.

Step-by-step filing flow

1. March-early April: log into Portal das Finanças, navigate to IRS → Modelo 3 → Entregar Declaração (Submit Declaration)
2. Choose form: select Auto-IRS if simple (likely insufficient for crypto holders); otherwise full Modelo 3
3. Quadro 1: filing status (single / joint / etc.)
4. Quadro 3: dependents
5. Anexos: tick which Anexos you need (A for salary, E for passive crypto yield, B if you run crypto as a business, G for crypto disposals, J for foreign income, etc.)
6. Fill each Anexo: data entry for each line item
7. Verify totals: AT auto-calculates tax owed across all Anexos
8. Submit: file electronically; you’ll receive a comprovativo (proof of submission)
9. Wait for assessment: AT processes returns through summer; refunds typically arrive late July - late August
10. Pay any balance due: usually by August 31 if you owe

Common filing errors

• Declaring crypto-to-crypto swaps: they aren’t taxable events, and putting them on Anexo G means paying tax you don’t owe and inflating your cost basis records
• Skipping Anexo G1 for 365+ day holds: the gain is exempt, but the disposal still goes on G1 Quadro 7 - exempt is not the same as undeclared
• Wrong cost basis: using disposal-date price instead of acquisition-date price - and forgetting that a swap carries the original acquisition value through
• Treating the mining coefficient as the crypto coefficient: 0.95 is mining only; other crypto operations are 0.15
• Opening a Cat B activity for ordinary staking: passive yield is Category E, and rewards paid in crypto aren’t taxed until disposal
• Missing Anexo SS for Cat B: Social Security declaration is separate from IRS; both are required

How are crypto gifts taxed and documented in Portugal?

Receiving crypto as a gift or inheritance is not IRS income - it’s a gratuitous transmission, which sits under stamp duty (Imposto do Selo) at 10% (verba 1.2 of the TGIS). The 10% applies when the crypto is held with an entity based in Portugal, when an inheritance comes from someone domiciled in Portugal, or when a lifetime gift’s recipient is domiciled in Portugal. Spouses, unido de facto partners, descendants and ascendants are exempt (CIS art. 6.º) - the typical family gift owes nothing.

The documentation still matters, three times over:

• Modelo 1 do Imposto do Selo - the transmission is declared by the end of the third month after it happens (CIS art. 26.º). Exempt close-family beneficiaries are generally dispensed from filing, but:
• The custodian release rule - an institution in Portugal cannot hand over gifted or inherited crypto without proof the stamp duty was paid or, where an exemption applies, that the declaration was filed (CIS art. 63.º-A). For custodied assets, the “dispensation” is theoretical - you’ll want the Modelo 1 comprovativo anyway.
• Your future cost basis - when you later sell, the acquisition value is the value used (or that would have been used) for stamp duty (CIRS art. 45.º), determined by official quotation or a declared value approximating market (CIS art. 14.º-A). Your 365-day clock also starts at the gift. Record the date and a valuation snapshot on the day you receive it.

On the other side: giving crypto away is not an onerous disposal, so the giver realises no Category G gain on the transfer.

What does AT already know about your crypto?

More than most filers assume, through two reporting channels:

• Domestic, since the regime began: entities providing crypto custody, administration or trading platforms must report their clients’ crypto operations to AT by the end of February each year (CIRS art. 124.º-A).
• EU-wide, from 1 January 2026: Lei n.º 26/2026 transposed DAC8, implementing the OECD’s Crypto-Asset Reporting Framework. Crypto-asset service providers across the EU now collect and report PT-resident users’ identification plus their purchases, sales, swaps, crypto payments and transfers to external wallets; the first exchanges of 2026 data reach tax authorities during 2027. Non-EU exchanges aren’t in DAC8, but most major jurisdictions are adopting the same CARF standard.

This means: your Modelo 3 declaration of crypto income should reconcile with what exchanges have reported to AT. Discrepancies will trigger questions - and the documentation set above is what answers them.

When to hire help

For a clean, single-exchange portfolio with mostly long-term holds: filing yourself is fine.

Get a contabilista if:

• You have >20 disposals in the year (the data entry alone is significant)
• You have DeFi or NFT activity (interpretive judgments needed)
• You have mining/staking with non-trivial revenue (recibos verdes, SS, coefficient choice)
• You’re a US person (FATCA + IRS overlap)
• You’ve just moved to PT with substantial pre-residency holdings

Typical contabilista fee for crypto-heavy filing: €300-€800 depending on complexity. Worth it if your portfolio is meaningful or if you’d rather not spend a weekend in spreadsheets.

Related reading

• Crypto tax in Portugal 2026 (full guide)
• Crypto mining and staking tax
• NFTs and DeFi tax
• Modelo 3 prep wizard
• How to file Modelo 3
• Crypto tax calculator

Sources

• Criptoativos — Conceito fiscal e tributação (AT official leaflet, Dec 2025, PDF)
• CIRS artigo 43.º — FIFO rule for crypto disposals (Portal das Finanças)
• CIRS artigo 45.º — acquisition value of assets received gratuitously (Portal das Finanças)
• CIRS artigo 128.º — duty to keep supporting documents four years (Portal das Finanças)
• Código do Imposto do Selo artigo 6.º — family exemption on gratuitous transmissions (Portal das Finanças)
• Código do Imposto do Selo artigo 26.º — Modelo 1 declaration deadline (Portal das Finanças)
• Código do Imposto do Selo artigo 63.º-A — release of values requires proof of payment or declaration (Portal das Finanças)
• Lei n.º 26/2026, de 3 de junho — DAC8/CARF transposition, crypto-provider reporting (Diário da República, PDF)