Expat Tax Software vs Accountant: Which Do Americans in the UK Need?

The expat tax software vs accountant decision turns on complexity, not income. An American in the UK with only a PAYE salary, a bank account and no UK investments can usually file a correct US return with expat tax software. Anyone with a UK pension they contribute to, UK funds or a Stocks and Shares ISA, a UK limited company, rental property or unfiled past years generally needs a US-UK specialist.

Both routes are legitimate. Software is cheaper and faster for simple cases, and the IRS accepts a self-prepared return like any other. However, software asks questions; it does not spot issues you did not know to mention. This guide gives a practical test for choosing between the two, based on the forms and treaty positions involved.

Expat tax software vs accountant: what each actually does

Expat tax software walks you through an interview and produces Form 1040 with the common expat forms: Form 2555 for the Foreign Earned Income Exclusion, Form 1116 for the foreign tax credit and Form 8938 for foreign assets. Most also guide you to file the FBAR, FinCEN Form 114, which is submitted separately and free through the FinCEN BSA E-Filing System.

What an accountant adds

A US-UK accountant does three things software cannot. First, they identify which rules apply to your UK assets before any form is chosen. Second, they take treaty positions, such as under the UK-US Income Tax Treaty, and disclose them on Form 8833 where required. Third, they coordinate your US return with your UK Self Assessment, so credits and timing line up across both. Our guide to questions to ask a US-UK tax adviser explains how to test that expertise.

Expat tax software vs accountant: when software is enough

Software is usually sufficient when your affairs fit a narrow pattern. You are employed in the UK and taxed under PAYE. Your only UK accounts are current and cash savings accounts. You hold no UK pension beyond a basic workplace scheme, no UK funds and no company shares in a business you control. You have filed every year, including FBARs. In that case, the main choice is between the exclusion and the credit, which good software handles.

The exclusion-versus-credit choice still matters

Even in simple cases, one decision deserves care. For 2026, the Foreign Earned Income Exclusion is $132,900 (IRS, 2026). However, UK Income Tax usually exceeds US tax, so the foreign tax credit on Form 1116 often gives a better long-term result, including eligibility for the refundable Child Tax Credit. Revoking the exclusion generally bars you from re-electing it for five years without IRS consent. Software will let you pick either; it will not tell you which suits your next five years.

Expat tax software vs accountant: when you need an accountant

Certain UK assets and events trigger US forms that consumer software either does not support or cannot complete without expert input.

PFICs: the most common trap

UK unit trusts, OEICs and most UK-domiciled ETFs are passive foreign investment companies (PFICs) for US tax. Each one needs Form 8621 each year, and the default tax treatment is punitive. The IRS estimates many hours of work per form in its Form 8621 guidance. Software that does not ask about UK funds will simply produce a return without them. That return looks complete, but it is not.

UK companies

If you own 10% or more of a UK limited company, Form 5471 applies. The penalty for failing to file is $10,000 per form, per year, under Internal Revenue Code section 6038 (IRS, About Form 5471). This is specialist work. Our US owners of UK companies page covers what is involved.

The hidden cost of getting it wrong

The real expat tax software vs accountant comparison is not one fee against the other. Instead, it is the fee against the cost of errors. In our experience, the most expensive returns we see are self-prepared ones that omitted a form. Information-return penalties often start at $10,000, and an incomplete return can keep the IRS's assessment period open under section 6501(c)(8). Consequently, a missed Form 8621 or Form 5471 can cost far more than years of professional fees.

An illustrative case

Consider an illustrative American in Leeds who filed with software for four years. The facts are illustrative. Their salary was reported correctly. However, they held index funds in a Stocks and Shares ISA and never filed Form 8621, because the software never asked. Fixing this required amended returns and PFIC calculations for each fund and year. A one-hour review in year one would have flagged the ISA and pointed them to US-compliant alternatives.

A middle route: software plus a review

You do not have to choose one route forever. Many clients self-file in simple years and take advice when something changes: a house purchase, a new pension, a company or a move. Alternatively, a one-off review of a self-prepared return can confirm that nothing is missing. If you are comparing professionals, our guide to the Enrolled Agent, CPA and Chartered Accountant credentials explains who can represent you before the IRS and HMRC.

What about Americans in the UAE?

The same test applies in Dubai. A salaried employee with a local bank account can often use software and Form 2555, because there is no UAE personal income tax to credit. However, owning a UAE free zone company brings Form 5471, and that again calls for a specialist. Our US expat tax returns page covers both countries.

If you are unsure where you fall in the expat tax software vs accountant decision, book a consultation with our US-UK tax team. We will tell you honestly whether you need us or whether software will do.

Frequently Asked Questions

Can I file my US expat tax return myself?

Yes, if your affairs are simple. An American abroad with only salary income, cash bank accounts and a complete filing history can usually self-file using expat tax software, claiming the Foreign Earned Income Exclusion on Form 2555 or the foreign tax credit on Form 1116, and filing the FBAR separately.

When do I need an accountant for US expat taxes?

You generally need a US-UK specialist if you hold UK funds or a Stocks and Shares ISA, contribute to a SIPP, own 10% or more of a UK company, have rental property, received a large foreign gift, or have missed past returns or FBARs. These trigger forms such as 8621, 5471, 3520 and 8833.

Does expat tax software handle PFICs?

Often not fully. Passive foreign investment company reporting on Form 8621 requires fund-by-fund calculations that many consumer products do not support. UK unit trusts, OEICs and most UK-domiciled ETFs are PFICs, so anyone holding them should take professional advice.

Is the FBAR included in expat tax software?

The FBAR, FinCEN Form 114, is not part of the tax return. It is filed separately through FinCEN's BSA E-Filing System at no charge. Some software will prepare or submit it for you, but you remain responsible for filing it by April 15, with an automatic extension to October 15.

Should I use the Foreign Earned Income Exclusion or the foreign tax credit in the UK?

Many Americans in the UK do better with the foreign tax credit on Form 1116, because UK Income Tax usually exceeds US tax on the same income. The Foreign Earned Income Exclusion is simpler, but revoking it generally prevents re-electing it for five years without IRS consent.

Do Americans in Dubai need an accountant for US taxes?

Not always. A salaried American in the UAE with simple finances can often self-file using Form 2555, since the UAE has no personal income tax. An accountant becomes necessary if they own a UAE company, hold foreign funds or have unfiled years.