What Britain Can Learn From International Wealth Taxes: Winckworth Sherwood Analysis

The UK is significantly broadening its tax base for accumulated wealth, shifting from domicile to a residence-based inheritance tax system starting April 2025. For fintech professionals and family offices, this move, combined with frozen thresholds and new property surcharges, necessitates a total reassessment of international asset structures and treaty protections.

What was announced

The Autumn Budget 2026 avoided a formal, comprehensive annual wealth tax, opting instead for targeted fiscal measures that widen the effective tax base. Key among these is the continued freeze of the £325,000 inheritance tax (IHT) nil-rate band through 2030–31, which uses fiscal drag to capture a larger proportion of estates as nominal asset values grow. Additionally, the Government is introducing a High Value Council Tax Surcharge (HVCTS) from April 2028, specifically targeting owners of higher-value English residential property.

Starting April 6, 2025, the principal connecting factor for IHT on overseas assets will shift from domicile to long-term UK residence. Individuals resident in the UK for at least 10 of the previous 20 tax years will face IHT on their global assets, with exposure potentially lasting between three and ten tax years after they leave the country. Furthermore, from April 6, 2027, most unused pension funds and death benefits will be integrated into estates for IHT purposes.

The analysis highlights international precedents, such as France’s Impôt sur la Fortune Immobilière, which generated approximately €2.2 billion from €467 billion of declared net taxable real-estate assets in 2024. It also notes that while OECD countries operating net wealth taxes fell from 12 in 1990 to four in 2017, nations like Norway and Switzerland maintain complex systems where migration does not always lead to a reduction in local business investment. The report emphasizes that existing treaties, such as the UK–Italy Estate Duty Convention, may still offer protections that override domestic residence-based rules.

The companies involved

Winckworth Sherwood is a prominent UK-based law firm that provides legal services to private clients, businesses, and non-profit organisations. Operating from its website at wslaw.co.uk, the firm has established a significant presence in the London legal market, particularly in sectors requiring complex advice on private wealth, real estate, and corporate law.

As an independent firm without a parent company, Winckworth Sherwood occupies a specific niche in the market, advising globally connected families, founders, and family offices on the intricacies of international tax law and asset protection. The firm’s expertise is particularly relevant in the current climate of shifting UK tax policy, where the transition from domicile-based to residence-based taxation creates significant administrative and strategic challenges for high-net-worth individuals. In the broader fintech and private wealth ecosystem, firms like Winckworth Sherwood act as critical intermediaries, helping clients navigate the intersection of domestic fiscal policy and international treaty obligations. Their analysis of the Autumn Budget reflects their role in interpreting how legislative changes impact the mobility and investment strategies of the international wealthy.

What this means

The UK is effectively implementing a wealth tax by stealth. By freezing thresholds and shifting to a residence-based model, the government is increasing the tax burden on accumulated capital without the political fallout of a headline-grabbing new tax. This puts immense pressure on the wealth management and fintech sectors to provide more sophisticated, real-time tracking of residence history and treaty eligibility. The move toward taxing pensions and high-value property suggests a long-term strategy of targeting illiquid wealth. For the fintech industry, the opportunity lies in developing tools that can model these multi-decade liabilities across different jurisdictions, as domicile ceases to be the primary shield for international assets.