International & Freelancer Taxes
US tax obligations follow US citizens and residents everywhere in the world. If you're an American engineer working abroad, you still owe taxes to the IRS. If you're freelancing on the side or full-time, you owe taxes that your clients won't withhold for you. Both situations create complexity that employed, US-based engineers don't have to think about — and getting them wrong results in penalties.
US Expat Taxes
The United States is one of only two countries that taxes its citizens on worldwide income regardless of where they live (the other is Eritrea). If you're a US citizen or green card holder working in Berlin, Tokyo, or Singapore, you still file a US tax return every year.
US citizen working in the UK:
UK salary: $180,000
UK income tax: ~$52,000 (paid to HMRC)
US tax obligation: Still must file and potentially pay
Without tax relief:
You'd pay tax to the UK AND the US on the same income.
That's double taxation.
With tax relief:
Foreign Tax Credit (FTC): Credit UK taxes paid against
US tax liability, dollar for dollar.
OR
Foreign Earned Income Exclusion (FEIE): Exclude up to
$130,000 of foreign earned income from US taxation (2025).
Foreign Earned Income Exclusion (FEIE)
The FEIE lets you exclude up to $130,000 (2025, adjusted annually for inflation) of foreign earned income from your US taxable income. To qualify, you must meet one of two tests:
Bona Fide Residence Test:
Be a resident of a foreign country for an entire tax year.
Having a lease, paying local taxes, and establishing a
life in the country supports this.
Physical Presence Test:
Be physically present in a foreign country for at least
330 full days during any 12-month period.
Partial days in the US count against you. Plan trips carefully.
The FEIE only applies to earned income (salary, wages, self-employment). It does not cover investment income, rental income, or capital gains. Also note the "stacking rule": the remaining taxable income above the exclusion is taxed at the rate that would apply to your full income, not starting from the bottom brackets.
Foreign Tax Credit (FTC)
The FTC is often better than the FEIE for high-income engineers, especially in high-tax countries:
FTC example (high-tax country like UK/Germany):
Foreign salary: $250,000
Foreign tax paid: $75,000
US tax on $250k: $52,000 (hypothetical)
FTC: Credit $52,000 of foreign taxes against US liability.
US tax owed: $0 (you paid MORE to the foreign country).
Excess credit: $23,000 (can carry forward/back).
FTC example (low-tax country like Singapore):
Foreign salary: $250,000
Foreign tax paid: $20,000
US tax on $250k: $52,000
FTC: Credit $20,000 of foreign taxes against US liability.
US tax owed: $32,000 (you still owe the difference).
In high-tax countries (most of Western Europe), the FTC usually eliminates your US tax liability entirely. In low-tax countries (Singapore, Dubai, Hong Kong), you'll owe the US the difference.
FEIE vs FTC: Which to Choose
Use FEIE when:
- You're in a low-tax or no-tax country
- Your income is under $130,000
- You don't have significant foreign taxes to credit
Use FTC when:
- You're in a high-tax country (UK, Germany, France, Japan)
- Your income exceeds $130,000
- You want to preserve access to US tax credits and deductions
(FEIE reduces your ability to contribute to IRAs, etc.)
Important: You can use FEIE and FTC together, but not on the
same income. You can exclude $130k with FEIE and use FTC on
the remainder.
Many expat tax advisors recommend FTC-only for high earners.
FEIE looks simpler but has hidden costs.
FBAR & FATCA
If you have foreign bank accounts, you have additional reporting obligations:
FBAR (FinCEN 114):
Required if: Aggregate value of all foreign accounts
exceeded $10,000 at any point during the year.
Due: April 15 (auto-extension to October 15).
Penalty for non-filing: Up to $12,500 per account per
year (non-willful), or the greater of $100,000 or 50%
of account balance (willful).
FATCA (Form 8938):
Required if: Foreign financial assets exceed $200,000
at year-end or $300,000 at any point during the year
(for expats; lower thresholds for US residents).
Filed with your tax return.
These are reporting requirements, not tax payments.
You're reporting the existence of accounts, not paying
additional tax on them. But the penalties for not filing
are severe.
Freelancer Taxes
Whether you're doing full-time freelance engineering or picking up contract work on nights and weekends, you need to handle taxes that your employer would otherwise manage for you.
Self-Employment Tax
Self-employment tax is the freelancer's version of FICA. As an employee, you pay 7.65% and your employer pays 7.65%. As a freelancer, you pay both halves:
Self-employment tax rate: 15.3%
Social Security: 12.4% (on income up to $176,100)
Medicare: 2.9% (on all income)
Additional Medicare: 0.9% (on income above $200,000)
On $100,000 of freelance income:
Self-employment tax: $14,130
Plus federal income tax: ~$17,000 (at ~24% effective)
Plus state tax (CA): ~$6,000
Total tax: ~$37,130 (37.1% effective rate)
Deduction: You can deduct 50% of self-employment tax
from your adjusted gross income. This reduces your income
tax (but not the SE tax itself).
Quarterly Estimated Taxes
Unlike employees, freelancers don't have taxes withheld from payments. Instead, you must pay estimated taxes four times a year:
Quarterly estimated tax due dates:
Q1: April 15
Q2: June 15
Q3: September 15
Q4: January 15 (of the following year)
How to calculate:
Option 1 (Safe Harbor - Prior Year):
Pay 100% of last year's tax liability, divided by 4.
(110% if AGI > $150,000)
Even if you owe more, no underpayment penalty.
Option 2 (Current Year Estimate):
Estimate this year's income and tax, pay 90%+ in
quarterly installments. Risk of penalty if you
underestimate.
Option 3 (Annualized Income):
If income is irregular, calculate tax based on actual
income received each quarter. More complex but more
accurate.
Underpayment penalties are modest (currently around 7-8% annualized on the underpaid amount) but avoidable. Use the safe harbor method if your income is predictable.
The 25-30% Rule
If you don't want to calculate quarterly estimates precisely, set aside 25-30% of every freelance payment for taxes. At higher income levels ($100k+), set aside 35-40% instead. The exact percentage depends on your marginal rate. Better yet, calculate it properly using IRS Form 1040-ES.
Business Deductions
Legitimate business expenses reduce your taxable freelance income:
Common deductions for freelance engineers:
Home office:
Simplified method: $5/sq ft, up to 300 sq ft = $1,500 max
Actual method: Percentage of home used for business applied
to rent, utilities, insurance, repairs.
Requirement: Space must be used EXCLUSIVELY and REGULARLY
for business.
Equipment:
Computer: Full deduction in year of purchase (Section 179)
Monitor, keyboard, desk: Same
Phone: Business-use percentage only (if 60% business,
deduct 60% of cost)
Software & services:
IDE licenses, cloud hosting, SaaS tools, domain names,
design tools — all deductible if used for business.
Professional development:
Courses, books, conference tickets, certifications —
deductible if related to your freelance work.
Internet:
Business-use percentage of home internet is deductible.
Health insurance:
If you're self-employed and not eligible for employer
coverage, self-employed health insurance premiums are
deductible (above-the-line, which is better than itemizing).
Retirement contributions:
Solo 401k: Up to $23,500 (employee) + 25% of net
self-employment income (employer), total up to $69,000.
SEP IRA: Up to 25% of net self-employment income,
max $69,000.
Both reduce taxable income.
When to Get an Accountant
Handle your own taxes if:
Simple situations you can manage yourself:
- W-2 income only
- W-2 income + small amount of 1099 income (< $10k)
- Standard deduction, no special circumstances
- Single state of residence, no foreign income
Use tax software (TurboTax, FreeTaxUSA) and save money.
Get a CPA or enrolled agent if:
Complex situations that warrant professional help:
- Full-time freelancing / self-employment
- Significant 1099 income (> $50k)
- Foreign income or foreign bank accounts
- Equity compensation (ISOs, NSOs, ESPP)
- Multi-state tax obligations
- Real estate rental income
- S-Corp or LLC election for freelancing
- You received an IRS notice or are being audited
Cost: $300-$1,500 for a good CPA, depending on complexity.
Value: Avoiding a $5,000 mistake or penalty makes this
worth it many times over.
Finding one: Ask other freelancers or self-employed engineers.
Avoid the big chains (H&R Block, Jackson Hewitt) for complex
situations. Look for a CPA who specializes in self-employment
or tech industry clients.
S-Corp Election
Once freelance income exceeds roughly 150k of freelance income, this typically saves $3-5k/year after accounting for additional compliance costs (accounting, payroll service, state filing fees). Talk to a CPA before making this election.
Common Pitfalls
- Not filing US taxes while abroad. US citizens must file regardless of where they live. Non-filing can result in penalties, loss of passport renewal, and inability to use FEIE or FTC retroactively.
- Choosing FEIE without understanding the consequences. The FEIE can limit your ability to contribute to Roth IRAs and affects the tax rate on your non-excluded income. Get professional advice.
- Not filing FBAR. The penalties for not reporting foreign accounts are disproportionately severe — up to $12,500 per account for non-willful violations. If you have any foreign accounts, file FinCEN 114.
- Not paying quarterly estimates. Waiting until April to pay your freelance taxes results in underpayment penalties. Set up quarterly payments even if they're rough estimates.
- Missing legitimate deductions. Many freelancers overpay because they don't track business expenses. Keep receipts, use a dedicated business bank account, and categorize expenses throughout the year.
- Setting aside too little for taxes. If you're freelancing at a high marginal rate, 25% isn't enough. Calculate your actual rate or use 35-40% as the set-aside percentage.
- Delaying the S-Corp election. If you're earning 3-5k in unnecessary self-employment tax. Talk to a CPA sooner rather than later.
Key Takeaways
- US citizens and green card holders owe taxes on worldwide income. Use the Foreign Tax Credit or Foreign Earned Income Exclusion to avoid double taxation, and file FBAR if you have foreign accounts.
- Freelancers pay self-employment tax (15.3%) on top of income tax. Set aside 25-40% of every payment for taxes, depending on your income level and marginal rate.
- Pay quarterly estimated taxes to avoid underpayment penalties. Use the safe harbor method (110% of prior year tax) for simplicity.
- Track and deduct all legitimate business expenses: home office, equipment, software, professional development, health insurance, and retirement contributions.
- Get a CPA when your tax situation involves foreign income, significant self-employment income, equity compensation, or multi-state obligations. The cost is small relative to the mistakes they prevent.
- Consider the S-Corp election when freelance income exceeds $80-100k to reduce self-employment tax. The math usually works in your favor after accounting for additional compliance costs.