Crypto Taxes for U.S. Expats in Portugal

U.S. tax on crypto abroad

U.S. citizens are taxed on worldwide capital gains, including gains from cryptocurrency, regardless of where they live. Crypto is treated as property for U.S. tax purposes. Gains and losses are reported on Form 8949 and Schedule D, with the holding period determining whether the gain is short-term or long-term. Crypto-to-crypto exchanges are generally taxable dispositions for U.S. purposes, and basis must be tracked in USD across wallets and exchanges.

Portuguese treatment

Portugal introduced a crypto tax regime effective January 1, 2023. Gains and losses on non-security crypto assets held for at least 365 days are excluded from taxation. Gains on assets held less than 365 days are generally taxed at an autonomous 28% rate, subject to the applicable aggregation rules and taxpayer-specific exceptions. Crypto-to-crypto exchanges of non-security crypto held less than 365 days are not taxed at the time of exchange; the received assets take the acquisition value of the assets delivered. Mining, validation, and issuance activities are treated as business or professional income, while remuneration from crypto investments can be investment income. The exit of Portuguese tax residency is treated as a disposal. Those Portuguese rules do not remove U.S. tax on the gain.

Reporting obligations

FinCEN Notice 2020-2 currently excludes foreign accounts holding only virtual currency from FBAR reporting. An account that also holds fiat currency or other reportable assets can still be reportable under the ordinary rules. Review the actual account and current guidance rather than assuming every exchange account must be reported. Form 8938 has a separate specified-foreign-financial-asset analysis; the FBAR notice does not decide it. A foreign fund holding crypto may also raise Form 8621 questions. Retain the account agreement, asset types, maximum values, and custody details.

FEIE and crypto

The FEIE does not apply to crypto gains. Crypto gains are capital gains, not earned income. Foreign tax paid on crypto gains may qualify for the Foreign Tax Credit, subject to sourcing and limitation rules. Because Portugal may defer or exclude some crypto gains, the foreign tax credit must be computed transaction by transaction rather than assumed.

Common mistakes

• Assuming a Portuguese holding-period exclusion eliminates U.S. tax.
• Ignoring basis tracking across exchanges and wallets.
• Treating crypto as currency rather than property for U.S. purposes.
• Ignoring fiat balances or other reportable assets in a foreign exchange account when reviewing FBAR obligations.
• Assuming crypto-to-crypto exchanges are non-taxable for U.S. purposes.
• Ignoring exit-tax consequences when leaving Portugal.

How U.S. basis and reporting work

For U.S. purposes, crypto is property. Every sale, exchange, payment for goods or services, or other disposition can create a gain or loss. Basis includes the purchase price plus fees, and it must be tracked separately for each wallet and exchange. Crypto-to-crypto exchanges are generally taxable dispositions, even when no fiat currency is received. A move between wallets under the same beneficial ownership is not a disposition. Short-term and long-term treatment depends on the holding period. Form 8949 and Schedule D report the transactions, and FBAR or Form 8938 may apply to foreign accounts or assets.

Records that support the return

Keep exchange CSV files, wallet addresses, transaction hashes, fee records, and documentation of acquisition dates and USD values. Reconcile internal transfers so the same units are not counted twice. If foreign tax was paid, keep assessments, withholding records, and proof of payment. If a position was lost, stolen, or became worthless, document the facts and dates before claiming a loss. If mining, staking, or airdrops occurred, keep records of the income recognized and any later disposition.

When the foreign result differs from the U.S. result

Portugal crypto rules may use different holding periods, pooling, cost formulas, or taxable events than the U.S. A foreign exemption, deferral, or reduced rate does not by itself remove U.S. tax. The Foreign Tax Credit is limited to qualifying foreign income tax on the same gain. Compute the U.S. result first, then reconcile the foreign tax to that result.

Planning the filing before the tax year closes

Before the year closes, reconcile every exchange and wallet, identify internal transfers, and compute USD gain or loss for each disposition. Decide whether any position qualifies for long-term treatment and whether foreign tax was paid on the same gain. If staking, mining, airdrops, or DeFi activity occurred, separate that income from capital gains. If a position became worthless or was stolen, document the facts and dates before claiming a loss. If the taxpayer is leaving the country, review exit-tax or deemed-disposal rules before changing residency.

A pre-filing review should also test whether foreign account reporting applies and whether the records can support the basis used. These questions are easier to answer before the return is filed than after an inquiry.

Scenarios that change the answer

A long-term holder who sells after a local exemption period may owe no foreign tax but still owe U.S. tax. A short-term trader may have business-income treatment in Canada or Australia but capital gain treatment in the U.S. A user who pays for goods or services with crypto triggers a disposition in both countries. A user who moves crypto between exchanges may create record gaps that make basis reconstruction difficult. A user who leaves the country may trigger exit or deemed-disposal rules before the U.S. recognizes income. A user who receives staking or mining rewards may have ordinary income at receipt and a separate gain or loss on later sale.

Avoiding duplicate taxation

Duplicate taxation is usually avoided through the Foreign Tax Credit, not through assuming the foreign result controls. The credit is limited to foreign income tax paid on income that is also subject to U.S. tax. If the foreign country exempts or defers the gain, there may be no credit even though U.S. tax is due. If the foreign country taxes a gain that the U.S. does not recognize, the credit may not be usable. Carryovers can help in later years but only within the same limitation category. Keep the foreign and U.S. computations aligned by transaction so the credit can be substantiated.

Filing checklist

Confirm the taxpayer's U.S. status and country of residence for the year. Confirm whether any foreign tax was paid and whether it qualifies for the credit. Reconcile exchange and wallet records to the return. Report each taxable disposition, including crypto-to-crypto exchanges. Review FBAR and Form 8938 thresholds. Keep records for at least the applicable assessment period and longer if a position is carried forward. If a foreign filing position differs from the U.S. position, keep both computations so the difference can be explained later.

Next steps

FileAbroad reviews the exchange, wallet, and transaction records to determine the U.S. reporting. Use the intake form to describe the assets, country, and tax years involved. See also: Crypto Taxes for U.S. Expats, FBAR Filing Guide.