Private Client
Form 3520, Form 709, Form 8621, SA109
Ongoing tax advice for wealthy families with US and UK ties, covering residence, investments, trusts, gifts and the estate position together.
What does Private Client involve?
Families with money in both countries tend to face the same questions each year: where each member is resident, how investments are held, what the trusts are doing, and what would happen on a death. We act as the family's tax adviser across both systems and keep those questions in one file.
Forms and filings involved
- Form 3520
Reporting for US persons who receive large gifts or inheritances from abroad or who deal with a foreign trust.
- Form 709
The US gift tax return, which Americans in the UK often need for gifts to a non-US spouse, children or property bought jointly.
- Form 8621
The annual return for US persons holding passive foreign investment companies, which includes most UK funds, unit trusts and ETFs.
- SA109
The Self Assessment pages for residence status, split-year treatment, treaty residence claims and foreign income and gains claims.
- US v UK
The structural differences between the US and UK income tax systems that cause most cross-border problems, from tax years to ISAs.
Advising families with wealth in both countries
Residence is reviewed first because everything follows from it.
UK residence is decided each tax year under the Statutory Residence Test, and since 6 April 2025 new arrivals after ten years of non-residence can claim the foreign income and gains regime for four tax years. US citizens remain within the US system wherever they live. In a family where some members are American and others are not, the same investment can suit one person and be expensive for another.
Inheritance tax on worldwide assets now depends on long-term UK residence, broadly residence in ten of the previous twenty tax years, rather than on domicile. US estate tax applies to citizens' worldwide estates above the $13.99 million basic exclusion, and to non-residents' US-situs assets above $60,000, before any treaty relief. A separate US/UK estate and gift tax treaty can reduce double taxation on death, and how it interacts with the new UK rules is something we review for each family.
Investment structure follows from both. A US family member holding UK funds faces the PFIC rules, while a UK-resident family member holding US funds may find they lack UK reporting fund status, which turns gains into income. Trusts and family companies add information returns in the US. We work with the family's investment managers so that each person's portfolio is built from holdings that suit their own tax position in both countries.
What we keep under review for a family
- 01
- Statutory Residence Test position for each family member every year
- 02
- UK inheritance tax exposure under the long-term residence rules
- 03
- US estate and gift tax position, including estate treaty relief
- 04
- Portfolio holdings checked against PFIC and UK reporting fund rules
- 05
- Trust distributions and reporting coordinated across both countries
Who this is for
Families where some members are American and others British
- Long-term UK residents holding substantial US investments or property
- Americans arriving in the UK with significant wealth
- Beneficiaries of trusts established in the other country
Why US UK Tax Returns
Each return is prepared with the other country's return open beside it, so a credit, election or disclosure on one is supported by the other.
One File
US and UK returns prepared in the same engagement and reconciled line by line.
Primary Sources
Every position traced to the Code, the treaty, IRS instructions or HMRC guidance.
Scope First
Returns, forms, years and fee agreed in writing before work begins.
The Same People
The team that files this year carries the elections and credits into the next.
Questions we are asked
We are British but hold US shares and a New York apartment. Are they exposed to US estate tax?
Potentially. US estate tax reaches a non-resident non-citizen's US-situs assets, which include US real property and shares in US companies, and the exemption without treaty relief is only $60,000. The US/UK estate and gift tax treaty can give substantial relief, including a proportionate share of the larger exclusion available to citizens, but it has to be claimed. How much relief applies depends on the size and make-up of the worldwide estate.
Why do my US index funds cause problems on my UK return?
Because most US-domiciled funds do not have UK reporting fund status. For a UK-resident investor, gains on disposing of a non-reporting offshore fund are generally taxed as income rather than as capital gains, so capital gains rates and the annual exempt amount do not apply. Some US funds do hold reporting status. The mirror problem affects Americans holding UK funds, so a mixed family often needs different holdings for different members.
Does the end of non-dom status change anything for my American husband?
It can. Since 6 April 2025 the remittance basis has gone, and new arrivals instead get a limited period of relief on foreign income and gains if they were previously non-resident for long enough. For a US citizen that relief is worth less, because the US taxes the income anyway. Inheritance tax on worldwide assets now depends on how long he has been UK resident, not on his domicile.
Primary sources
What this page says is drawn from the official material below. Read it yourself; we would rather be checked than trusted.
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