International Wills: Ensuring Your Estate Plan Is Valid Everywhere

A will that works perfectly in one country may be entirely ineffective in another. For internationally mobile individuals with assets or family ties in multiple jurisdictions, the risk of dying with an estate plan that is valid in name but unenforceable in practice is real. Properties, bank accounts, and investments can become frozen for years while competing legal systems argue over who governs the succession. Children may find that forced heirship rules in a foreign country override what their parent clearly intended.

The answer is not to have one will that "covers everything" — it is to have a carefully coordinated estate plan that is legally valid and practically effective in every jurisdiction where it needs to operate. This guide explains how international will planning works, what makes a will valid (and invalid) across borders, and the strategies available to internationally mobile individuals.

Why One Will Is Rarely Enough

The common assumption is that a UK will drafted by a reputable solicitor is sufficient to dispose of all worldwide assets. In practice, this assumption breaks down for several reasons:

Formal Validity Requirements

Each country has its own requirements for a will to be formally valid — the minimum age of the testator, how many witnesses are required, whether the testator must sign personally, whether a notary must be present. A UK will signed in front of two witnesses (valid under English law) may not be formally valid in a country where notarisation is required.

Language

A will in English must typically be translated into the local language before a foreign court, notaire, or land registry will act on it. Certified translation adds time and cost; mistranslations or ambiguities can be contested.

Recognition of Legal Concepts

Common law concepts — trusts, executors, probate — may not translate directly into civil law systems. A French notaire confronted with a UK trust provision in a will may be uncertain how to treat it. Spanish land registries may require a Spanish will or a Spanish court order to transfer Spanish real estate.

Forced Heirship

As noted in the article on the EU Succession Regulation, civil law countries reserve compulsory shares of the estate for certain family members regardless of the will's contents. A UK will that attempts to leave the entire estate to a single beneficiary will be partially overridden in France, Spain, and many other jurisdictions.

Revoking Earlier Wills

Standard will drafting in England often includes a clause revoking "all previous wills". Where a person has made a local will in France or Spain and subsequently makes a UK will with a revocation clause, the local will may be inadvertently revoked. This is one of the most common and damaging errors in multi-jurisdiction estate planning.

Approaches to International Will Planning

Approach 1: The Hague Convention International Will

The Washington Convention of 1973 (also called the Convention Providing a Uniform Law on the Form of an International Will) introduced a specific type of will — the "international will" — designed to be formally valid in all signatory countries. As of 2026, signatories include many significant jurisdictions.

An international will must:

• Be in writing (any language, handwritten or typed).
• Be signed by the testator personally in the presence of an "authorised person" (typically a notary or solicitor acting in an equivalent capacity) and two witnesses.
• Have the authorised person attach an "Annex" certificate confirming compliance with the convention requirements.

If executed correctly, an international will should be recognised as formally valid throughout all signatory jurisdictions without further formality. This does not resolve substantive law questions (such as forced heirship) — it only addresses formal validity.

The UK is not a signatory to the Washington Convention in its own right (though some UK legal practitioners can act as authorised persons in certain contexts). In practice, international wills are not widely used in UK-based estate planning; most practitioners prefer the multi-will approach described below.

Approach 2: Separate Wills for Each Jurisdiction

The most common and practical approach for internationally mobile individuals with significant assets in multiple countries is to have separate wills for each jurisdiction — one UK will dealing with UK assets, and one local will (in the country's language, drafted by a local notary or lawyer) dealing with assets in that country.

The advantages are:

• Each will is drafted to comply with local formal validity requirements.
• Each will is in the local language, making it immediately usable by local institutions.
• Local practitioners can advise on local substantive law (forced heirship, succession taxes) and draft accordingly.
• Probate in each country can proceed in parallel rather than waiting for a foreign grant to be recognised.

The critical requirement is coordination: the wills must be drafted consistently to avoid:

• Inadvertent revocation (each will should state clearly that it applies only to assets in the relevant jurisdiction).
• Contradictory provisions (the same asset cannot be given to two different beneficiaries in two different wills).
• Tax inefficiency (the combined succession tax position must be optimised, not left to chance).
• Inconsistent law elections under Brussels IV (the EU Succession Regulation).

A coordinating solicitor — typically in the UK — working with local lawyers in each jurisdiction is the usual approach. The UK solicitor should receive and review all local wills to ensure overall consistency.

Approach 3: Single Will with Foreign Ancillary Provisions

A single UK will can sometimes be made more internationally effective by:

• Including an express governing law election (for EU member states, under the Brussels IV Article 22 election for English law as the law of the testator's nationality).
• Including specific provisions dealing with foreign property in terms that translate into the relevant foreign legal concepts.
• Apostilling the document and including certified translations for each relevant country.

This approach avoids the coordination complexity of multiple wills but is less likely to be accepted smoothly by foreign institutions, who generally prefer a local document.

Formal Validity: The Hague Convention on Conflicts of Laws

Separate from the Washington Convention, the Hague Convention on the Conflicts of Laws Relating to the Form of Testamentary Dispositions (1961) is more widely ratified. It provides that a will is formally valid if it complies with the law of:

• The testator's domicile at the time of execution or death.
• The place where the will was executed.
• The testator's habitual residence at the time of execution or death.
• The testator's nationality at the time of execution or death.
• The location of the assets (for immoveable property).

The UK is a signatory to the 1961 Convention, and most EU member states have implemented it. This means that a UK will executed in compliance with English law requirements can be recognised as formally valid in most EU countries under the Convention — even without a local will. However, recognition of formal validity does not guarantee recognition of its substance (including any choice of law or executor provisions).

Executing a Will Abroad

If a UK national executes a will while residing abroad, the will should be:

• Executed in compliance with English law requirements (or the law of the chosen jurisdiction) to ensure formal validity.
• Signed before witnesses who are not beneficiaries (to avoid invalidating gifts to witnesses).
• Dated and kept in a safe location with instructions to the executor(s).
• Notarised if the country of residence requires it for local recognition.

A UK solicitor can provide draft instructions and, in some jurisdictions, remote witnessing may be possible through video link under procedures introduced after COVID-19 — though this is an evolving area and physical witnessing remains preferable where practical.

Executors in Multiple Jurisdictions

Appointing executors who can practically operate in each relevant jurisdiction is often overlooked. A UK executor may not be able to deal effectively with:

• A French bank that requires a French notaire to manage the estate.
• A Spanish property that can only be transferred through the Spanish notarial system.
• A Cyprus bank account that requires local probate proceedings.

Consider appointing co-executors who are resident in the relevant country, or granting the primary executor the power to appoint local agents. Some professional trustees and trust companies have offices in multiple jurisdictions and can act as executor across borders.

Digital Assets

A growing concern for internationally mobile individuals is the succession of digital assets — cryptocurrency wallets, online investment accounts, digital business interests, intellectual property stored digitally. Standard will provisions may not address digital assets adequately.

Key steps:

• Include digital assets in the will (a general "all my assets" clause should suffice, but specific reference reduces uncertainty).
• Provide the executor with access instructions (ideally via a secure password manager or sealed letter — not in the will itself, which becomes a public document on probate).
• Confirm whether digital asset platforms have their own succession processes.
• Take legal advice in each relevant jurisdiction on how digital assets are treated for succession and tax purposes.

Succession Taxes: A Separate Issue

A valid will does not guarantee tax efficiency. Each country where assets are located may impose its own inheritance or succession tax:

• UK: IHT on worldwide assets for long-term residents; on UK-situated assets for non-residents.
• France: Droits de succession — rates depend on relationship between deceased and beneficiary, and assets' value.
• Spain: Impuesto sobre sucesiones — varies by autonomous community; can be substantial.
• Germany: Erbschaftsteuer — significant for larger estates.
• Cyprus: No inheritance tax.
• UAE: No inheritance tax.
• Thailand: Inheritance tax applies (since February 2016) only on inherited assets exceeding 100 million baht per estate — 5% for direct ascendants/descendants, 10% for other heirs; estates below that threshold are untaxed (property transfer taxes apply separately).

Double tax treaties between the UK and other countries sometimes provide relief against paying IHT in both countries on the same assets, but the UK's network of estate tax treaties is limited. Local succession tax planning must proceed in each jurisdiction alongside will drafting.

Reviewing Your International Estate Plan

An international estate plan requires regular review. Triggers for review include:

• Change in country of residence or habitual residence.
• Change in nationality (obtaining a second passport affects Brussels IV election options).
• Acquisition or disposal of assets in a new jurisdiction.
• Major family events: marriage, divorce, birth of children or grandchildren, death of an intended beneficiary.
• Changes in the law in any relevant jurisdiction.

As a minimum, a full review every three to five years — or on any major life event — is advisable.

How Global Investments Can Help

At Global Investments, we work with internationally mobile individuals whose estate planning challenges cross multiple legal systems and tax regimes. We coordinate with specialist estate planning lawyers in each of our primary markets — the UK, UAE, Cyprus, Spain, Thailand, Greece, Egypt, and Bali — and beyond, to ensure that our clients' plans are coherent, legally robust, and tax-efficient in every jurisdiction that matters.

We help clients to:

• Map their assets across jurisdictions and identify will and estate planning gaps.
• Coordinate the drafting of consistent multi-jurisdiction will structures.
• Integrate the Brussels IV Article 22 election where appropriate.
• Address digital asset succession.
• Optimise succession tax planning across all relevant jurisdictions.
• Review and update plans regularly as circumstances change.

Estate planning that works in every jurisdiction where you need it is not a luxury — it is the only reliable protection for everything you have built. All information in this guide reflects the position as of 2026. Legal requirements change and vary significantly by jurisdiction; please seek professional legal advice in each relevant country before finalising your estate plan.