Cross-Border Divorce: Key Wealth Planning Considerations for US/UK Families

Written by Henry Findlater

As of 2023, the most recent year with available official data, there were 102,678 divorces in England and Wales, with divorce rates of 8.6 per 1,000 married men and 8.5 per 1,000 married women.¹ With increasing global mobility, a growing number of these divorces involve individuals whose financial and personal ties span multiple countries, often between the UK and the United States. For dual UK-US families, divorce presents a uniquely complex blend of emotional, legal, and financial challenges. At MASECO Private Wealth, we work closely with internationally connected clients to ensure that, during this pivotal life transition, their cross-border financial interests are carefully protected and strategically managed. Below, we highlight ten essential considerations to help US and UK individuals navigate divorce with clarity and confidence.

1. Determine Jurisdiction Early

Jurisdiction can materially affect the outcome of a divorce. In the UK, courts focus on fairness and have broad discretion in how they divide marital property. In contrast, the US operates under state-specific rules, with some applying community property principles while others follow equitable distribution.

Some US states, such as California, automatically treat all assets acquired during marriage as community property, while others, such as New York, consider a wider array of equitable factors including income disparity and future earning capacity. In high-asset divorces, the choice of forum can have a major impact on outcomes.

When couples have ties to more than one country, they may be eligible to initiate proceedings in either. Identifying the most favourable jurisdiction should be an early and strategic decision.

2. Understand the Tax Implications of Citizenship-Based Taxation

The US is one of only two countries in the world that impose taxation based on citizenship rather than residency.² US citizens and green card holders must report and pay tax on their worldwide income, regardless of where they live or where the income is earned.

During divorce, this can lead to surprising outcomes. For example, a UK-domiciled individual receiving alimony from a US person may not be taxed in the UK, while the US payer receives no deduction post-2018 under the Tax Cuts and Jobs Act. Pre-2019 divorce decrees may still allow deduction and inclusion treatment under grandfathered IRS rules.³

Without cross-border tax coordination, a seemingly fair split of income or assets can result in significantly disproportionate after-tax outcomes.

3. Evaluate All Assets with Dual Jurisdiction in Mind

Each jurisdiction may classify and tax assets differently. A UK-based investment fund may be efficient locally but could be treated as a Passive Foreign Investment Company (PFIC) under US tax law. PFICs are subject to harsh tax treatment, including interest charges on deferred gains and the loss of capital gains treatment.²

Conversely, many US mutual funds do not carry UK reporting fund status and may generate “offshore income gains” taxed not at capital gains tax rates, but at UK income tax rates.

Before agreeing to any financial settlement, it is crucial to review assets under both UK and US tax regimes. This analysis helps identify assets that may be inefficient or even toxic for one spouse due to their tax residency or citizenship status.

4. Plan Carefully Around Pensions

Pensions frequently represent a significant portion of marital wealth. Both UK and US courts may issue pension sharing orders, but their interpretation and tax treatment differ.

A British spouse receiving part of a US pension plan such as a 401(k) or IRA may be required to pay US tax on withdrawals. Moreover, if the recipient is not a US person, they may face mandatory 30% withholding tax unless treaty relief is claimed.³

Meanwhile, UK Lifetime Allowance (LTA) rules, though not in force for tax year 2025–26, still affect many legacy pension arrangements and may require tracking benefit crystallisation events. Complexities around Qualified Domestic Relations Orders (QDROs) in the US also need to be understood, as not all retirement plans are covered and early withdrawal penalties can apply if not handled properly.

5. Consider the Real Tax Cost of Real Estate

Real estate is often both emotionally and financially significant, but cross-border ownership complicates matters. In the UK, a spouse may benefit from Principal Private Residence Relief, but a US citizen may still face capital gains tax under IRC § 121, which provides only a $250,000 exclusion for individuals and $500,000 for married couples.⁴

Currency movements can also cause unexpected taxable gains. If a US citizen assumes a UK mortgage and the GBP weakens against the dollar, the IRS may treat this as a foreign currency gain under IRS rules.⁴

For US taxpayers, real estate settlements should be reviewed for both capital gains exposure and foreign exchange tax risk.

6. Draft or Review Prenuptial and Postnuptial Agreements Across Jurisdictions

Prenuptial and postnuptial agreements can be useful tools, but they are treated differently in the UK and the US. In many US states, these agreements are enforceable provided they meet formal requirements. In the UK, prenuptial and postnuptial agreements are not automatically legally binding but may be upheld by the courts if deemed fair, entered into freely, supported by legal advice, and based on full financial disclosure. Since the landmark 2010 Radmacher v Granatino decision, which significantly raised the profile of these agreements, the legal landscape surrounding divorce continues to evolve.

Couples with cross-border exposure should ensure any agreement is drafted with both jurisdictions in mind. Provisions on asset division, spousal support, and jurisdiction clauses should be tailored carefully. Agreements should also be reviewed periodically, especially following major life changes such as relocation, childbirth, or a significant shift in net worth.

7. Anticipate the Full Divorce Process Timeline

Under the UK’s no-fault divorce regime, couples can now jointly file for divorce without assigning blame. This has simplified the legal process, but financial settlements still require comprehensive disclosure and careful negotiation.

The process generally includes filing the application, serving and acknowledging the application, applying for a Conditional Order after a minimum period of twenty weeks, and applying for a Final Order at least six weeks and one day later.

When the divorce involves international pensions, trusts, or businesses, timelines often extend well beyond this. Delaying the financial consent order can risk loss of entitlement or jurisdictional enforceability.

8. Model Post-Divorce Scenarios Through Financial Planning

At MASECO, we help clients answer a fundamental question: will I have enough?

Using sophisticated financial modelling tools, we help clients analyse capital sufficiency, project cash flow, test various “what-if” scenarios, and explore the impact of market volatility. This clarity empowers clients to approach negotiations with confidence and to build a secure financial future post-divorce.

9. Identify Hidden Tax Traps

Assets that look similar in value may behave very differently after tax. Examples include UK ISAs, which are not tax-advantaged in the US and may need to be reported annually on PFIC forms. Similarly, US mutual funds often lack UK reporting fund status and may be taxed at income tax rates in the UK.²

Foreign currency loans, deferred compensation, non-US trusts, and even frequent flyer points may trigger tax issues or require disclosure in either jurisdiction. Failure to disclose US foreign financial assets may result in penalties under FATCA and FBAR rules.⁵

It is essential to work with advisors who understand the cross-border tax implications of each asset class.

10. Coordinate Advisors Across Borders

The most successful divorces from a financial perspective are those where advisors collaborate early. Coordination between wealth managers, legal counsel, and cross-border tax experts helps reduce the risk of missteps, saves costs, and ensures that settlements are practical and enforceable across jurisdictions.

At MASECO, we work closely with family lawyers and international tax advisors to deliver fully aligned support for clients undergoing complex transitions.

Conclusion

Divorce is never easy, but for internationally mobile families, the stakes are significantly higher. Tax exposure, legal uncertainty, and asset complexity can erode long-term wealth if not proactively managed.

At MASECO Private Wealth, we specialise in helping US and UK families navigate these transitions with clarity, control, and strategic foresight. If you are a US-connected individual contemplating or navigating divorce, we encourage you to speak with our team. With expert guidance and coordinated planning, you can take the next step with confidence.

Sources

1. Office for National Statistics, “Divorces in England and Wales,” 2021
   User guide to divorce statistics – Office for National Statistics
2. Internal Revenue Code §§ 61, 1291–1298, PFIC rules
   https://www.law.cornell.edu/uscode/text/26
3. IRS Publication 504, Divorced or Separated Individuals
   https://www.irs.gov/publications/p504
4. Internal Revenue Code §§ 121, 988 — Capital Gains and Currency Taxation
   https://www.law.cornell.edu/uscode/text/26
5. IRS FATCA and FBAR Reporting Comparison
   https://www.irs.gov/businesses/comparison-of-form-8938-and-fbar-requirements

The Legal Stuff

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