Denmark Tax Guide for US Citizens

US Citizenship-Based Taxation Fundamentals

• Worldwide income: The US taxes US citizens on their worldwide income, regardless of where they live. This means: (a) you must file a US tax return (Form 1040) every year, even if all your income is Danish, (b) you report all Danish income (salary, rental, dividends, capital gains, pensions) in USD on your US return, and (c) you claim the Foreign Tax Credit (Form 1116) or Foreign Earned Income Exclusion (Form 2555) to avoid double taxation.
• Dual filing obligation: You file a Danish tax return (årsopgørelse) and a US tax return (Form 1040) each year. The Danish return is due 1 July (with extensions). The US return is due 15 April (automatic extension to 15 October for expats via Form 4868). The US also requires FBAR filing by 15 April (automatic extension to 15 October).
• Foreign Earned Income Exclusion (FEIE): Under IRC §911, US citizens living abroad can exclude up to ~$126,500 (2026, indexed) of foreign earned income (salary, self-employment income) from US taxation. The exclusion requires either: (a) the physical presence test (330 full days outside the US in any 12-month period), or (b) the bona fide residence test (resident in a foreign country for an uninterrupted period including a full tax year). The FEIE reduces the amount of Danish income subject to US tax but also reduces the foreign tax credit available (since the excluded income generates no US tax against which to credit Danish tax).
• Foreign Tax Credit (FTC): Under IRC §901, US citizens can credit Danish income taxes paid against their US tax liability on the same income. The FTC is per-country and per-income-category (passive vs general). The credit is limited to: (Danish tax paid) or (US tax on the foreign-source income), whichever is lower. Excess credits can be carried back 1 year and forward 10 years. The FTC is generally more beneficial than the FEIE for high-income earners in Denmark (where Danish tax rates are higher than US rates, no additional US tax is due).
• Severe penalty regime: Failure to file US tax returns or FBAR as a US citizen abroad carries severe penalties: $10,000 per unfiled FBAR (willful: greater of $100,000 or 50% of account balance), $10,000 per unfiled Form 8938 (FATCA), and $5,000+ for late-filed Form 1040. The IRS Streamlined Foreign Offshore Procedures (SFOP) allow non-willful late filers to catch up with reduced penalties — but this is a one-time amnesty.

US-DK Tax Treaty Key Provisions

• Dividends (Article 10): 5% WHT on dividends from ≥10% ownership, 15% for portfolio. Danish WHT on dividends paid to US residents is reduced under the treaty.
• Interest (Article 11): 0% WHT. Interest from US sources paid to Danish residents is not subject to US WHT. Danish interest paid to US residents is exempt from Danish WHT.
• Royalties (Article 12): 0% WHT in both directions.
• Pensions (Article 18): Pensions (including US 401(k), IRA distributions, and US Social Security) are taxable only in the country of residence (Denmark for Danish residents). However, the US retains the right to tax distributions from US retirement accounts if US tax was deferred — this creates potential dual taxation. The treaty's savings clause (Article 1(6)) preserves the US right to tax its citizens on US-source income, including pension distributions. In practice, US 401(k) and IRA distributions are taxable in both the US (as US-source income under the savings clause) and Denmark (as worldwide income). The Danish foreign tax credit provides relief.
• Savings clause (Article 1(6)): This critical provision means the US reserves the right to tax its citizens as if the treaty had not come into effect. The treaty benefits that reduce US tax for non-US persons generally do not apply to US citizens. For example, the pension article (Article 18) would give Denmark sole taxing rights over US pension distributions — but the savings clause preserves US taxing rights over US citizens on those distributions.
• Limitation on Benefits (Article 22): Comprehensive LOB clause requiring the recipient of treaty benefits to be a qualified person (publicly traded, owned by qualified persons, or conducting active business). US citizens and US-owned Danish companies must satisfy the LOB to claim treaty benefits on Danish-source income.

FATCA and FBAR Reporting

• FBAR (FinCEN Form 114): File electronically if the aggregate value of all foreign financial accounts exceeds $10,000 at any point during the calendar year. Accounts covered: Danish bank accounts (NemKonto, ordinary checking/savings), investment accounts (investment funds, brokerage accounts), pension accounts (ratepension, livrente, aldersopsparing), and accounts where you have signatory authority (e.g., company accounts). The threshold is very low — most US citizens with any Danish accounts must file. Due: 15 April, with automatic extension to 15 October.
• FATCA (Form 8938): File with Form 1040 if specified foreign financial assets exceed: $50,000 (single, living in Denmark) or $100,000 (married filing jointly) on the last day of the tax year, or $75,000/$150,000 at any time during the year. Assets covered: Danish bank/investment accounts, Danish pension funds, Danish life insurance with cash value, and foreign non-publicly-traded entities you own (e.g., a Danish ApS you control). The FATCA filing threshold is higher than FBAR but the scope is broader.
• Danish banks and FATCA compliance: Danish banks are required by the Denmark-US IGA to report US citizen account holders to SKAT, which transmits the data to the IRS. This means: (a) the IRS already knows about your Danish accounts, (b) any failure to report will be detected through automatic matching, and (c) ensure your Danish bank knows your US citizenship (provide Form W-9 and sign the FATCA self-certification). Some Danish banks have declined or closed accounts for US citizens due to compliance costs — shop around if needed.
• Streamlined Foreign Offshore Procedures (SFOP): If you have unfiled FBARs or FATCA forms, the IRS Streamlined Program allows you to file the last 3 years of tax returns and last 6 years of FBARs with a reduced penalty of 5% of the highest aggregate account balance. You must certify that the failure was non-willful. This program is available to US citizens living abroad — it is a one-time amnesty.

PFIC Rules — Danish Investment Funds

The US Passive Foreign Investment Company (PFIC) rules (IRC §§1291–1298) are the single most punitive US tax issue for US citizens in Denmark who invest in Danish funds:

• What is a PFIC: Any non-US company (including Danish investment funds — investeringsforeninger, ETF'er, and certain unit-linked pension products) that has ≥75% passive income or ≥50% passive assets is a PFIC. Most Danish mutual funds, index funds, and ETFs are PFICs. Even some Danish pension products (e.g., unit-link investments in foreign funds) may be PFICs.
• PFIC tax treatment (default — Section 1291): The default PFIC regime is punitive: (a) gains on disposition are allocated over the holding period, (b) the gain allocated to prior years is taxed at the top marginal rate for each year, (c) an interest charge is added for each year of deferred tax, and (d) dividends and capital gains are taxed at ordinary income rates (not the lower 15-20% capital gains rate). This means Danish index funds (designed for tax efficiency in Denmark) produce disastrous US tax outcomes.
• QEF election (Section 1295): If the Danish fund provides a PFIC Annual Information Statement (AIS), you can make a Qualified Electing Fund (QEF) election to be taxed annually on your share of the fund's ordinary earnings and capital gains (rather than on disposition). Few Danish funds provide AIS statements. For those that do (some large Danish funds), the QEF election eliminates the interest charge but requires annual reporting of the fund's undistributed income.
• Mark-to-market election (Section 1296): For PFICs that are publicly traded (most Danish ETFs and larger funds), you can make a mark-to-market (MTM) election. Under MTM, you include the excess of the fund's year-end market value over your adjusted basis as ordinary income each year. Losses are deductible to the extent of prior MTM gains. This is administratively simpler than QEF but converts capital gains to ordinary income.
• Practical advice: US citizens in Denmark should not hold Danish investment funds in taxable accounts unless they have professional US tax advice. Consider: (a) holding only individual stocks (not funds) in Danish taxable accounts, (b) holding US-domiciled ETFs and mutual funds (which are not PFICs) through a US brokerage account — the IRS recognises these as qualified dividends eligible for lower rates, (c) using Danish pension accounts (ratepension, livrente) for fund investments — the PFIC rules still apply but the mark-to-market election is easier to manage within a pension wrapper, and (d) the aktiesparekonto (ASK) — fund investments in an ASK are still PFICs for US purposes, so individual stocks are preferred.

US Retirement Accounts (IRA, 401k) in Denmark

• Taxation of IRA/401k distributions: US IRA and 401k distributions are taxable in Denmark as pension income (personlig indkomst at progressive rates). Under the treaty, Denmark has primary taxing rights as the residence country. However, the US savings clause preserves US taxing rights — so the distribution is also taxable in the US (subject to the foreign tax credit for Danish tax paid). The Danish foreign tax credit on US-source pension income may not cover the full US tax due because the credit is per-country and per-income-category. In practice, the combined US-DK tax on IRA distributions can exceed the Danish tax alone — plan distribution timing carefully.
• Roth IRA: Roth IRA distributions are US-tax-free (qualified distributions). In Denmark, the distribution is taxable as ordinary income — Denmark does not recognise the Roth wrapper. The full distribution (including the earnings that were tax-free in the US) is subject to Danish tax. This creates a situation where Roth IRA distributions are taxed in Denmark but generate no US foreign tax credit (because no US tax is paid). Consider converting to a traditional IRA before retirement to at least generate a US tax liability that can be credited.
• Roth conversion: Converting a traditional IRA to a Roth IRA while resident in Denmark: (a) the conversion amount is taxable in the US (ordinary income in the conversion year), (b) it is also taxable in Denmark as worldwide income, (c) the Danish foreign tax credit applies to the US tax paid on the conversion. Roth conversions should be done in years when Danish income is low to minimise the combined tax cost. Professional advice is essential — the interaction between US and Danish taxation of Roth conversions is complex.
• Danish PAL tax on foreign pension accounts: Danish PAL tax (15.3% on investment returns) does not generally apply to US 401(k)s and IRAs held in the US (the PAL tax applies only to Danish-approved pension schemes). However, if you transfer a US pension to a Danish QROPS-approved scheme, the PAL tax will apply annually to the investment returns within the Danish scheme.

Social Security Totalisation Agreement

The US-DK Social Security Totalisation Agreement (effective 2008) prevents dual social security taxation and ensures contribution periods are aggregated for benefit entitlement:

• Coverage rules: You are generally covered by the social security system of the country where you work. If you work in Denmark, you pay Danish AM-bidrag (8%) and ATP — not US Social Security (FICA) and Medicare taxes. Your US employer does not pay the employer's share of FICA/Medicare.
• Certificate of coverage (COC): If you work for a US employer while living in Denmark, you may remain covered by US Social Security for up to 5 years under the agreement. Your US employer applies to the Social Security Administration for a Certificate of Coverage (Form SSA-2032). You present this to SKAT to prove you are exempt from Danish AM-bidrag and ATP. After 5 years, Danish coverage begins.
• Aggregation of credits: US and Danish social security credits are aggregated for benefit entitlement. If you have 10 years of US credits and 15 years of Danish credits, the SSA and the Danish Pension Agency (Udbetaling Danmark) aggregate them for your combined US and Danish state pension. You must apply to each agency separately for benefit determination at retirement age.
• Self-employment: Self-employed US citizens in Denmark pay Danish AM-bidrag and ATP. They are not subject to US self-employment tax (SECA) on Danish self-employment income if the Totalisation Agreement applies. A COC is required to prove exemption from SECA.

Practical Compliance Checklist

• US tax return: File Form 1040 annually by 15 April (extension to 15 October). Include Form 1116 (Foreign Tax Credit) to credit Danish taxes paid. Include Form 8938 (FATCA) if assets exceed thresholds. Include Form 2555 (FEIE) if claiming the foreign earned income exclusion.
• FBAR: File FinCEN Form 114 electronically by 15 April (extension to 15 October). Report all Danish bank, investment, and pension accounts exceeding $10,000 aggregate.
• Danish tax return: File årsopgørelse by 1 July. Report all US income (dividends, interest, capital gains, US pension distributions, US Social Security).
• PFIC compliance: For Danish fund holdings, file Form 8621 annually for each PFIC. This form is notoriously complex — expect to need professional assistance. Consider applying the mark-to-market election (Form 8621 Section B) for publicly-traded funds.
• Currency conversion: Report all DKK amounts on US returns in USD using the average annual exchange rate (for recurring income) or the spot rate (for transactions). The IRS accepts SKAT's official exchange rates for Danish purposes.
• State filing: Check whether your last US state of residence requires a state tax return as a non-resident. Some states (e.g., California, New York) aggressively pursue former residents for state income tax on certain income types.
• Professional advice: US-DK cross-border tax is one of the most complex areas of international taxation. Engage a US-licensed CPA or EA with international experience, ideally one who also understands Danish tax. The cost of professional compliance ($2,000–$5,000/year) is far less than the cost of penalties for unfiled FBARs.

See our Tax Treaties Guide → for the full US-DK treaty rate table, our Expat Arrival Guide → for initial setup, and Investment Guide → for Danish investment products.