Insights & Perspectives
Deep-dive analysis spanning aggressive market horizons, regulatory frameworks, and operational tax strategies.
Written by the people who prepare the returns
Cross-border tax goes wrong in predictable places. A UK adviser treats an ISA as tax free, a US adviser treats a SIPP like a 401(k), and nobody checks how the two returns fit together. These guides cover the points where the two systems disagree, with the form numbers, thresholds and deadlines that apply.
Each one answers a question we are asked in practice: whether you still have to file from the UK, how to catch up without penalties, what happens to an ISA on a US return, how UK pensions are treated under the treaty, and which foreign account forms you need. Where a rule comes from the IRS, FinCEN or HMRC, we link to the source so you can check it yourself.
For the work itself, see our services or the page for your situation.
Latest Insights
UK LLP US Tax: How American Doctors and Lawyers in UK LLPs Are Taxed
HMRC treats a UK LLP as a partnership; the IRS treats it as a corporation unless the firm elects otherwise. What that means for a US citizen partner's return, self-employment tax, Form 8865 and foreign tax credits.
Accountants for US and UK Businesses: What Founders Need on Both Sides
A business with companies, staff or customers in both countries files with Companies House, HMRC, the IRS and a US state. What each side expects, how the treaty and transfer pricing connect them, and what to ask an adviser.
Mark-to-Market PFIC Election: When It Beats the Default Rules
Section 1296 taxes a foreign fund's yearly rise in value as ordinary income instead of top-rate tax plus interest on sale. Which funds qualify, how the loss limit works and when the election wins.
National Insurance for Americans in the UK: What You Pay and What It Buys
Most Americans working in Britain pay UK National Insurance, but a US secondment can keep you in US Social Security. The 2026/27 rates, the totalization agreement and what your contributions buy.
US UK Trust and Estate Tax Planning: The Basics Every Cross-Border Family Needs
The US taxes estates by citizenship, the UK by long-term residence, and the two treat trusts in almost opposite ways. The rules that matter, the traps for mixed-nationality couples and what to review first.
HMRC Worldwide Disclosure Facility: Fixing Undeclared US Income
US dividends, rent or gains that never reached your UK return can be put right through HMRC's Worldwide Disclosure Facility. The 90-day process, how many years you go back, and how the offshore penalties are set.
US/UK Cross Border Tax Preparation Checklist: Every Document to Gather
A dual filer needs more than a W-2 and a P60. Two tax years overlap, account balances are reported at their highest point and days in each country have to be counted. A document-by-document checklist.
PFIC Tax Calculation: The Excess Distribution Method With a Worked Example
The default PFIC rules spread a gain over every day you held the fund, tax the earlier years at the top rate and add interest. Each step of the arithmetic, with real numbers.
Inheriting US Assets as a UK Resident: Tax When a US Parent Dies
Receiving the inheritance is rarely the taxable moment in either country. The tax arrives afterwards, and an inherited IRA, a fund portfolio and a US house are three different problems for someone living in the UK.
UK Property Company for a US Citizen: The US Tax Consequences of Holding Property Through a Ltd
A limited company is the standard UK answer to Section 24. For a US citizen it is also a foreign corporation, with Form 5471, the CFC rules and a PFIC trap attached. What the structure does on each side, and when it still works.
Inheritance From a UK Parent as a US Citizen: Tax and What to Report
An inheritance from a parent in the UK is usually not taxed in your hands in either country. It is reportable to the IRS above a threshold, and what you do with it afterwards is taxed.
The 31 October Paper Self Assessment Deadline: Who Still Files on Paper and Why
Most people can ignore 31 October and file online by the end of January. Some cannot use HMRC's online service at all, and for them the paper date is three months closer than they think.
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