Complex holdings, two tax authorities, one coordinated position.
Multiple income sources, entities and investment accounts across both countries — plus two estate tax regimes with very different thresholds. At this level the cost of poor coordination compounds quickly.
Every asset sits in two systems at once
Carried interest, restricted stock, partnership income and trust distributions each map differently onto the two codes. The planning is in the interactions: which country's relief to use where, what to hold in which wrapper, when to realise gains and in which currency.
- Both personal returns plus entity and trust filings
- Investment structuring that works in both systems
- Estate and gift planning across both thresholds
- Year-round advice, not just filing season
Estate exposure is the quiet one
UK inheritance tax starts at £325,000; the US estate exemption is measured in millions. Domicile, situs and the 1979 estate treaty decide which regime bites. Planning while options remain open is most of the value we add.
What we typically handle for you
- Both personal returns plus entity and trust filings
- Investment structuring across both systems
- Estate and gift planning against both thresholds
- Carried interest and partnership income treatment
- Trust reporting: 3520 / 3520-A
- Property portfolios on both sides
- Charitable giving that relieves in both countries
- Year-round advice, not just filing season
The services that usually apply
Questions we get about this
Yes, and it usually improves the outcome. Investment decisions made without the cross-border tax view are where most avoidable cost enters.
We are generally reviewing what is proposed rather than proposing investments ourselves.
They can be, in both directions. Non-reporting funds can be taxed as income by HMRC, and non-US funds are usually PFICs to the IRS.
Products marketed as tax-efficient in one jurisdiction are frequently the opposite in the other.
Earlier than most people begin. The structures that work well across both systems generally need time to be put in place and to season.
Retrofitting an estate plan after a diagnosis or a move is where options are most limited.
Routinely. We tend to sit alongside wealth managers, solicitors and family offices rather than replace them, covering the cross-border tax layer specifically.
That layer is usually where the gap is, because it needs qualification on both sides at once.
Potentially to both. US estate tax and UK inheritance tax work on different bases and can each claim the same assets.
An estate and gift tax treaty allocates between them, but it needs applying deliberately rather than assumed.
Non-US funds, offshore bonds and certain trust arrangements can carry heavy US reporting and unfavourable treatment even where they are entirely ordinary locally.
The reporting burden is often the larger issue, because penalties attach to filings that raise no tax.
Related pages
- Who we help
Founders & equity holders
Founders and equity holders across the US and UK: options, QSBS, EIS/SEIS and exits taxed on both sides of the Atlantic.
- Service
Trusts & estates
Cross-border trusts, gifts and inheritance: US-UK estate planning, foreign trust reporting and the forms that catch families out.
- Pillar guide
Tax specialists for US and UK
What US and UK tax specialists handle that a general accountant does not: residence tests, treaty relief, FBAR, PFICs, pensions, property and catch-up filings.
- Service
Property & capital gains
Cross-border property and capital gains: selling a home, rental income, currency gains and the 60-day UK reporting deadline, handled on both returns.
- Who we help
Families & trusts
Cross-border families: gifts, inheritances, trusts and the reporting that catches ordinary family planning, including children with US citizenship.
- Glossary
PFIC: definition
Passive Foreign Investment Company — the US label that catches most UK funds, and why it hurts.
Further reading
- Two legal systems, one estate, and a valuation everyone needs
An estate with assets on both sides of the Atlantic needs two administrations, and they run on different timetables. The documents that serve both are worth gathering once.
- Building a financial plan when two tax systems both claim you
Most cross-border mistakes are not technical. They happen because two competent advisers each optimise half a position, and nobody owns the join between them.
- Year-end planning when your household has two year ends
Most households get one deadline to act before. A household inside both systems gets two, and the moves that help on one side can cost real money on the other.
Last reviewed . Thresholds and rates change annually — check figures against the current tax year before relying on them.
Assets and advisers across both countries?
We cover the cross-border tax layer alongside your existing team. Tell us how things are structured.