Americans Building Businesses in Asia Pacific: The US Tax Rules That Follow Them

Asia Pacific has become one of the most attractive regions in the world for American founders, executives and remote professionals. Singapore and Hong Kong offer low tax rates and deep capital markets. Australia, Japan and New Zealand offer talent, stability and fast-growing tech scenes.

What many newcomers underestimate is that their US tax obligations travel with them. The United States is one of only two countries that taxes its citizens on worldwide income regardless of where they live.

A move to Singapore does not end the requirement to file a US return every year, and US tax returns for Americans living abroad often involve foreign company, pension and investment reporting that local accountants never see.

How US citizenship-based taxation works abroad

US citizens and green card holders must report their worldwide income to the IRS annually. Two main tools prevent most people from paying tax twice.

The Foreign Earned Income Exclusion lets qualifying Americans exclude up to $132,900 of foreign wages or self-employment income for tax year 2026. The Foreign Tax Credit gives a dollar-for-dollar credit for income tax paid to another country.

Which tool works better depends heavily on where you live. That is why the same American can face very different US outcomes in Sydney and in Singapore.

Low-tax hubs: Singapore and Hong Kong

Singapore’s top personal income tax rate is 24%, and Hong Kong’s salaries tax is capped by a standard rate of 15% to 16%. Both are well below US federal rates for high earners.

That gap matters. When local tax is lower than US tax, the Foreign Tax Credit cannot fully cover the US bill. Americans in these hubs often rely on the Foreign Earned Income Exclusion, and high earners may still owe the IRS on income above the exclusion limit. Investment income, capital gains and carried interest are not covered by the exclusion at all.

Neither Singapore nor Hong Kong has a Social Security totalization agreement with the United States. Self-employed Americans in these cities may owe US self-employment tax of 15.3% on their net earnings even when they pay nothing similar locally.

Local retirement schemes add another layer. Contributions to Singapore’s CPF and Hong Kong’s MPF are not automatically recognised as tax-deferred retirement savings by the IRS, and the accounts often need to be reported.

High-tax markets: Australia, Japan and New Zealand

Australia’s top marginal rate is 45%, Japan’s combined national and local top rate exceeds 50%, and New Zealand’s top rate is 39%. In these countries, the Foreign Tax Credit usually wipes out US tax on salary income, and excess credits can carry forward for up to ten years.

The risks sit elsewhere. Australian superannuation is a frequent source of confusion for Americans, since its US treatment differs from its Australian treatment and the accounts carry their own reporting duties. Australia and Japan both have totalization agreements with the United States, so employees and self-employed people can usually avoid paying social security taxes to both countries, provided they obtain the right certificate.

When an American owns an Asian company

Many Americans in the region set up a local company, whether a Singapore Pte Ltd, a Hong Kong limited company or an Australian Pty Ltd. For US purposes, this triggers Form 5471 for most owners, and if Americans control the company, its profits may be taxed in the US before any dividend is paid.

In low-tax jurisdictions this has real cost implications. A company paying Singapore’s 17% headline corporate rate falls below the 18.9% threshold for the US high-tax exception, so careful planning around salary, dividends and elections becomes essential.

Investments and bank accounts

Asia Pacific Americans often invest through local brokers and funds. Most non-US mutual funds and ETFs are treated as passive foreign investment companies (PFICs) by the IRS, which brings punitive tax treatment and a separate annual form for each fund.

Bank and investment accounts also carry disclosure rules. An FBAR is required when the combined value of foreign accounts exceeds $10,000 at any point in the year. FATCA reporting on Form 8938 applies at higher thresholds, starting at $200,000 for single filers living abroad.

Country snapshots

Singapore

Singapore offers low personal income tax rates and generally no capital gains tax, but Americans living there still have US tax obligations. Understanding US expat taxes in Singapore is especially important for income exceeding the Foreign Earned Income Exclusion, self-employment tax, CPF reporting, and Form 5471 requirements for certain business owners.

Hong Kong

Territorial taxation and low rates make Hong Kong attractive, but the US still taxes worldwide income. MPF accounts and local company ownership require careful US reporting.

Australia

High local rates usually eliminate US tax on wages. Superannuation, Australian managed funds and self-employment for ABN holders are the areas where Americans most often need specialist help.

Japan

High local tax and a totalization agreement simplify the wage picture. Japanese investment trusts and NISA accounts can create PFIC issues.

Getting the structure right early

The most expensive US tax problems in Asia Pacific usually come from decisions made in the first year: how a company is set up, where savings are invested and whether US returns continue on time. Americans who fall behind can often catch up without penalties through IRS relief programs, but staying compliant from the start is simpler.

Universal Tax Professionals, a CPA-led US expat tax firm serving Americans in more than 150 countries, prepares US returns for Americans across Asia Pacific, including complex cases involving foreign companies, PFICs and Streamlined Filing. Every client works with a dedicated accountant who understands both the US rules and how they interact with local systems across the region.