How to Make an International Will: One Will or Several, Choice of Law and the 8 Steps

This guide explains what an "international will" actually is, whether you can or should have a will in two countries, how the EU Succession Regulation and the UK's own conflict rules work, and then sets out the eight practical steps for putting a cross-border will in place without one document undoing another.

What is an international will?

An international will means two different things, and confusing them is the first common mistake. In everyday use it simply describes a will, or a set of wills, that deals with assets or family in more than one country. In the strict legal sense it is a specific form of will created by the Convention providing a Uniform Law on the Form of an International Will, adopted in Washington on 26 October 1973 under the auspices of UNIDROIT.

The Washington Convention does not harmonise who inherits. It creates an optional, uniform way of signing a will so that the document is valid as to form wherever it was made, wherever the assets are and whatever the testator's nationality, domicile or residence, in every country that has adopted it. The testator declares before two witnesses and an "authorised person" that the document is their will, signs it in their presence, and the authorised person attaches a certificate in a prescribed form.

The catch is coverage. According to UNIDROIT's status table, the convention entered into force on 9 February 1978 and has only 13 contracting states: Australia, Belgium, Bosnia-Herzegovina, Canada, Croatia, Cyprus, Ecuador, France, Italy, Libya, Niger, Portugal and Slovenia. Australia joined most recently, with effect from 10 March 2015. The United Kingdom signed on 10 October 1974 and the United States on 27 October 1973, but neither has ratified.

The UK position is particularly easy to misread. Parliament did legislate: sections 27 and 28 of the Administration of Justice Act 1982 would give the convention's annex the force of law and name solicitors and notaries public as the authorised persons. But legislation.gov.uk still marks those provisions as prospective, meaning they have never been brought into force. For a client based in England, an "international will" in the Washington sense is therefore not a domestic option, and the practical question becomes how to make ordinary wills that work across borders.

Can I have a will in two countries?

Yes. You can have a will in two countries, or in several, and for people who own real estate abroad it is often the more practical route. The alternative is a single worldwide will that deals with everything. Neither is automatically right: the choice depends on where the assets are, how quickly each country's authorities will act on a foreign document, and how carefully the documents are coordinated.

A single will is simpler to keep consistent, but executors may need to have it recognised, translated and sometimes re-proved in each country where assets sit, which can be slow. Separate "situs" wills, each limited to the assets in one country and drafted in that country's form and language, can speed up local administration. Their weakness is the interaction between them: two documents signed at different times, by different advisers, in different languages, can contradict each other or, worse, revoke each other.

Factor	One worldwide will	Separate wills for each country
Consistency	One set of gifts and executors, low risk of conflict	Gifts and definitions must be aligned across documents
Local administration	Foreign authorities may require translation and local proof of the will	Each will is already in local form and language
Revocation risk	None between documents	High if a revocation clause is drafted too widely
Executors	One executor or team, who may lack local standing	Local executors can be appointed for local assets
Updating	One document to review	Every will must be reviewed whenever one changes
Best suited to	Modest foreign assets, mainly financial, in few countries	Real estate abroad, or several countries with distinct procedures

Whichever structure you choose, the documents must agree on the most basic question: which law governs the estate as a whole. That is where the real cross-border planning lies.

Is a will made abroad valid in the UK?

A will made abroad is generally valid in England and Wales as to form if it was properly executed under any one of several connected laws. Section 1 of the Wills Act 1963 treats a will as properly executed if its execution conformed to the internal law of the territory where it was signed, or of the territory where the testator was domiciled or habitually resident, or of a state of which they were a national, either when the will was signed or at death.

That generous rule reflects an international treaty. The Hague Convention of 5 October 1961 on the Conflicts of Laws Relating to the Form of Testamentary Dispositions uses the same connecting factors, adds the law of the place where immovable property is situated for wills of land, and applies the same rules to a will that revokes an earlier one. It is far more widely adopted than the Washington Convention: the Hague Conference's status table lists 42 contracting parties, including the United Kingdom, for which it entered into force on 5 January 1964, alongside Spain, France, Germany, Switzerland, Japan, Australia and South Africa.

Two cautions apply. First, formal validity only answers whether the will was signed properly; it says nothing about whether its gifts can take effect under the law that governs the succession. Second, some countries do not apply the Hague rules at all, so a will that is formally valid in London may still face questions elsewhere. Formal validity is necessary but not sufficient.

Which country's law decides who inherits?

The law that decides who inherits depends on which country's courts and authorities are asking the question, and for estates touching the EU the starting point is Regulation (EU) No 650/2012, the EU Succession Regulation. It applies to the estates of people who die on or after 17 August 2015.

Under Article 21, unless the regulation provides otherwise, the law governing the succession as a whole is the law of the state where the deceased had their habitual residence at the time of death. By exception, if it is clear from all the circumstances that the deceased was manifestly more closely connected with another state, that state's law applies instead. Article 20 makes the rule universal: the law identified applies even if it is not the law of an EU member state, so a court in Spain can apply English law, or Thai law, if the regulation points there.

The governing law covers far more than people expect. Article 23 lists, among other things, who the beneficiaries are and their shares, the rights of a surviving spouse or partner, disinheritance, the powers of executors, liability for debts and "the disposable part of the estate, the reserved shares" and other restrictions on what a person may leave by will. In other words, whether children or a spouse have fixed inheritance rights that a will cannot override is decided by the governing law, not by the wording of the will.

Not every EU state takes part. Recital 82 records that the United Kingdom and Ireland did not take part in adopting the regulation and are not bound by it, and recital 83 records the same for Denmark. A UK court therefore applies its own conflict of laws rules rather than the regulation, which is one reason the same estate can be analysed differently in London and in Madrid, and why planning should test the outcome in each country that will deal with the estate.

Question	EU Succession Regulation answer	Where to check
Which law governs by default?	Habitual residence at death	Article 21(1)
Can I choose another law?	Yes, the law of a nationality you hold	Article 22
Does it apply to non-EU law?	Yes, the chosen or default law applies whatever the state	Article 20
Does it cover forced shares?	Yes, reserved shares and the disposable part	Article 23(2)(h)
Is the will's form valid?	Valid if it meets any of five connected laws	Article 27
Does it cover joint property and pensions?	No, excluded from scope	Article 1(2)(g)
From when?	Deaths on or after 17 August 2015	Article 83(1)

How to make an international will: the 8 steps

Making an international will is a sequence: map, decide, draft, sign, coordinate and review. The order matters, because decisions about governing law and structure must be made before any document is signed.

1. Map every asset and how it is held. List each asset by country: land and buildings, bank and investment accounts, company shares, pensions, life insurance and valuables. Note how each is owned, because joint ownership with a right of survivorship, pension plans and insurance contracts pass outside the will and are excluded from the EU regulation's scope. Real estate needs special attention, since the ownership rules for foreign buyers differ sharply between countries, and local real estate and property lawyers can confirm how title is registered.
2. Establish your connecting factors. Record your nationalities, where you are habitually resident now, where you expect to live in future and, for UK purposes, your domicile and tax residence history. These facts decide which law applies by default and what choices are open to you.
3. Decide which law should govern the estate. Compare the default outcome with the law of your nationality. If you live in an EU state that recognises reserved shares for children but want the freedom of testation your home law allows, a choice of law under Article 22 may be the central planning tool.
4. Choose one will or several. Use the comparison table above. If you choose several, define the scope of each will precisely by country or by asset class, and make sure no asset falls between them or is covered twice.
5. Draft the revocation clauses with care. Each will must revoke only earlier wills dealing with the same assets. A standard clause revoking "all former wills" in the second document can cancel the first.
6. Sign each will in a form that will be accepted. Follow the formalities of the country where the will will be used, even if a looser rule might technically suffice, because local registries and banks act faster on documents in a familiar form. For Spanish assets, for example, family and private client advisers in Spain can confirm the expected local form.
7. Coordinate executors and administration. Appoint executors who can act where the assets are, or give the main executor power to appoint local agents. Within the EU, heirs and executors can apply for a European Certificate of Succession to prove their status in other member states.
8. Store, record and review. Tell your executors where every will is kept, keep a schedule cross-referencing the documents, and review all of them together whenever you marry, divorce, move country, buy or sell a foreign property, or change any one will.

The steps can be summarised as follows.

Step	Key output	Typical risk if skipped
1. Map assets	Asset schedule by country and ownership type	Assets left out or passing outside the will unexpectedly
2. Connecting factors	Nationality, residence and domicile record	Wrong assumption about which law applies
3. Governing law	Decision on default law or a choice of law	Forced shares overriding your wishes
4. Structure	One will or defined set of wills	Gaps or overlaps between documents
5. Revocation	Limited revocation clauses	A later will cancelling an earlier one
6. Execution	Each will signed in accepted form	Delay or refusal by local authorities
7. Executors	Executors able to act in each country	No one with local authority to deal with assets
8. Review	Storage record and review triggers	Outdated or inconsistent documents

Choosing the law of your nationality in a will

A choice of law is the most powerful clause in many cross-border wills. Article 22 of the EU regulation lets a person choose, to govern their succession as a whole, the law of the state whose nationality they hold either when making the choice or at death. Someone with several nationalities may choose any of them.

The choice must be made expressly in a declaration in the form of a disposition of property upon death, such as a will, or be demonstrated by the terms of such a disposition. An explicit clause is far safer than relying on implication. Nationality is the only option: you cannot choose the law of the country where you own a villa simply because the villa is there, and you cannot choose the law of a country where you merely live. People who hold or are acquiring a second passport, for instance through citizenship by investment, gain an extra option, but only for a nationality actually held at the relevant time.

British nationals need one extra step. Because the United Kingdom has more than one legal system, Article 36 directs a nationality choice, absent internal rules, to the law of the territorial unit with which the person had the closest connection, so a well-drafted clause names the relevant system, such as the law of England and Wales, rather than "UK law".

Older wills are protected. Under Article 83, a choice of law made before 17 August 2015 is valid if it meets the regulation's conditions or the private international law rules in force when it was made, and a will made before that date in accordance with a law the testator could have chosen is deemed to choose that law. Even so, older wills are worth reviewing, because an express choice leaves less room for argument than a deemed one.

The revocation clause trap when you have two wills

If you have two wills, the risk is that the later one revokes the earlier. In England and Wales, section 20 of the Wills Act 1837 provides that a will may be revoked by another will or codicil executed in the required manner, by a written declaration executed like a will, or by destruction with the intention of revoking it.

Most professionally drafted wills open with a clause revoking all earlier wills. That clause is harmless when there is only one will, and destructive when there are two. If a client signs an English will covering everything "except my property in Spain" but leaves in a general revocation clause, the English will may revoke the Spanish will signed a year earlier, leaving the Spanish property without a valid will at all. The reverse can happen when a Spanish will is signed after the English one.

The solution is careful drafting and sequencing. Each will should revoke only earlier wills dealing with the same assets, should expressly preserve the other will by date and description, and should be reviewed by advisers in both countries before signature. The documents should also use consistent definitions, so that "my children" or "my residuary estate" mean the same thing in each.

Signing formalities: getting each will executed properly

Each will must be signed in a form that is valid and, ideally, familiar where it will be used. The GOV.UK guide to making a will sets out the basic requirements in England and Wales: you must be 18 or over, make the will voluntarily and be of sound mind, make it in writing, and sign it in the presence of two witnesses who are both over 18, who then sign in your presence. You cannot leave your witnesses, or their married partners, anything in your will.

The same guide flags exactly the situations this article covers as ones where you should get professional advice, including where your permanent home is outside the UK and where you have property overseas. That is a fair signal that cross-border wills are not a do-it-yourself exercise.

Other countries have their own formalities, and local advisers should confirm what registries and banks there expect to see. Where the Washington Convention applies, its form adds its own sequence: the will is in writing in any language, the testator declares before two witnesses and the authorised person that it is their will and that they know its contents, the signatures go at the end, each sheet is signed and numbered, and the authorised person attaches the certificate. The certificate is conclusive of formal validity unless there is evidence to the contrary, although a missing or defective certificate does not by itself invalidate the will. The convention does not cover joint wills made by two people in one instrument.

Tax is a separate question from your will

A will decides who receives your assets; it does not decide which countries tax them. Inheritance and estate taxes follow their own connecting factors, and several countries may claim the same estate.

In the UK the test changed fundamentally on 6 April 2025. According to HMRC's guidance on long-term UK residents, the domicile and deemed domicile rules were replaced by long-term residence rules: a person is a long-term UK resident in a tax year if they were UK tax resident for the previous 10 consecutive years, or for 10 or more of the previous 20 years, and their overseas assets may then be within the scope of Inheritance Tax. Long-term residence can continue for up to 10 tax years after leaving the UK, with shorter periods for those with fewer years of residence; for example, someone with 10 to 13 years of UK residence stops being a long-term resident three years after leaving.

Our analysis of how long you must live outside the UK to escape the inheritance tax tail explains the timing in detail, and our guide to becoming non-resident for UK tax covers the statutory residence test that feeds into it. Because tax depends on residence history while succession law may depend on habitual residence or nationality, the two analyses should be run side by side, ideally with local and international tax advisers in each country involved.

Assets that pass outside your will

Some of the most valuable assets never pass under a will at all. Article 1(2)(g) of the EU regulation excludes from its scope property passed otherwise than by succession, for instance by gifts, joint ownership with a right of survivorship, pension plans and insurance contracts. These pass under their own terms, usually through nominations or beneficiary designations held by the pension provider or insurer.

Matrimonial property regimes are also excluded, under Article 1(2)(d), so the property rights that flow from a marriage are decided under separate rules from the succession itself, and what a surviving spouse already owns under the regime may never form part of the estate. Couples who married in one country and now live in another should check which regime applies to them, a question explored in our international divorce guide, which covers how jurisdiction and assets are dealt with across borders.

The practical point is that an international will can only be as good as the asset map behind it. Beneficiary designations should be reviewed at the same time as the wills, and structures such as trusts and holding companies, which asset protection specialists often use, need their own succession provisions.

Common mistakes in cross-border wills

The biggest mistake in an international will is assuming that one country's rules will be applied everywhere. Others recur often enough to list:

• A general revocation clause. A second will that revokes "all former wills" can cancel the first.
• No express choice of law. Relying on habitual residence when you meant your home law to apply leaves heirs exposed to reserved shares.
• Choosing an unavailable law. Under the EU regulation, only the law of a nationality you hold can be chosen.
• Ignoring marriage. GOV.UK notes that getting married cancels any will made before in England and Wales, so a cross-border marriage may silently undo the English will.
• Overlapping definitions. Two wills that both leave "my residuary estate" create an argument about which one governs which assets.
• Forgetting non-will assets. Joint accounts, pensions and life policies pass on their own terms.
• Changing one will only. Every amendment is a prompt to review all the others; GOV.UK points out that the only way to change a will is a formally executed codicil or a new will.

Disputes and enforcement across borders

When cross-border estates are contested, the forum matters as much as the law. Under Article 4 of the EU regulation, the courts of the member state where the deceased was habitually resident at death have jurisdiction over the succession as a whole, and Article 35 allows a court to refuse a foreign law only where applying it would be manifestly incompatible with its public policy. Within the EU, a European Certificate of Succession produces its effects in all member states without any special procedure, and third parties who pay or transfer property in reliance on it are protected.

Outside the EU framework, executors may need to bring separate proceedings in each country or have a judgment recognised abroad, a process we describe in our guide to enforcing a foreign judgment. In England, probate and trust claims now sit in the Property, Trusts and Probate List of the High Court's new Business and Property Division, as explained in our guide to how the former Chancery Division's work is now organised. Clear, consistent wills are the best protection against reaching that stage.

When to bring in an adviser

Bring in an adviser as soon as your estate touches a second country, and certainly before signing a second will. The work typically needs a lead adviser in the country where you live and a correspondent in each country where significant assets sit, coordinated so that the documents are drafted together rather than in sequence.

Corporate INTL's directory of family and private client advisers lists firms that handle cross-border wills and succession, and you can also search by country, for example advisers in England, France or Portugal, two of the countries that apply the Washington Convention. Where the estate includes investment portfolios or family businesses, a wealth management adviser can help align the wills with the wider structure.

Frequently asked questions

How do I make an international will?

Map your assets by country, establish your nationality and habitual residence, decide which law should govern your estate, choose one will or several, draft revocation clauses that protect each document, sign each will in a form accepted locally, appoint executors able to act abroad, and review all the wills together after any major life change.

Can I have a will in two countries?

Yes. Many people with property abroad hold separate wills, each limited to the assets in one country. The wills must be drafted together, with consistent definitions and revocation clauses that cancel only earlier wills covering the same assets, otherwise the later will can revoke the earlier one.

What happens if I have two wills?

If both are valid and each deals with different assets, both can operate side by side. If the later will contains a general clause revoking all former wills, or covers the same assets, it can revoke the earlier will in whole or in part, leaving assets passing under the wrong document or under intestacy rules.

Is a will made abroad valid in the UK?

Usually, as to form. The Wills Act 1963 treats a will as properly executed if it complied with the law of the place where it was signed, or of the testator's domicile, habitual residence or nationality when it was signed or at death. Whether its gifts take effect is a separate question for the governing law.

Does a UK will override a Spanish will?

Not automatically. Which will prevails depends on their dates, their revocation clauses and the assets each covers. Spain applies the EU Succession Regulation, so the law of habitual residence governs unless the will validly chooses the law of the testator's nationality, which a British national can do.

Is the UK a party to the international will convention?

No. The UK signed the 1973 Washington Convention on 10 October 1974 but has not ratified it. The Administration of Justice Act 1982 contains provisions to give it effect, but they are marked as prospective and have never been brought into force, so the international will form is not available under UK law.

Can my beneficiary live in another country?

Yes. A will can leave assets to people or charities anywhere, but payment across borders may raise tax, currency and reporting issues in the beneficiary's country, and the governing succession law may still give fixed shares to close family that limit what can go to others.

What automatically revokes a will in England and Wales?

A will is revoked by a later will or codicil, by a written declaration signed like a will, or by destruction with the intention of revoking it. Marriage also cancels a will made before it. Moving country is not on that list, but it can change which law governs the estate.

Do I need a lawyer to make an international will?

GOV.UK says you can write a will yourself but should get advice if your will is not straightforward, expressly including where your permanent home is outside the UK or you have property overseas. Given the revocation and choice of law risks, cross-border wills generally justify advice in each country involved.

Sources

1. UNIDROIT: Convention providing a Uniform Law on the Form of an International Will (Washington, 1973)
2. UNIDROIT: Status of the 1973 Washington Convention on international wills
3. Administration of Justice Act 1982, Part IV: International wills (legislation.gov.uk)
4. Wills Act 1963, section 1: General rule as to formal validity (legislation.gov.uk)
5. Wills Act 1837, section 20: Revocation of wills (legislation.gov.uk)
6. HCCH: Convention of 5 October 1961 on the Conflicts of Laws Relating to the Form of Testamentary Dispositions
7. HCCH: Status table for the 1961 Testamentary Dispositions Convention
8. EUR-Lex: Regulation (EU) No 650/2012 on succession and the European Certificate of Succession
9. GOV.UK: Making a will
10. GOV.UK: Inheritance Tax if you're a long-term UK resident

About this article

This guide was researched and written by The Corporate INTL Newsroom, which covers cross-border legal, regulatory and business developments for lawyers, professional advisers and financiers in over 150 jurisdictions. It has been checked against the text of the Washington and Hague conventions and their official status tables, the EU Succession Regulation, UK legislation and GOV.UK guidance. It describes general rules, mainly from the perspective of England and Wales and the EU; the law of other countries and individual circumstances can change the answer. This article is general information, not legal or tax advice; for advice on a specific estate, consult a qualified adviser in each country involved. Last reviewed 27 October 2026. For more analysis like this, visit the Corporate INTL newsroom or subscribe to Corporate INTL.