Joint Will vs Mirror Will vs Single Will: Which Is Right for You? (2026)

When couples start thinking about wills, three terms come up repeatedly: joint will, mirror will, and single will. They sound similar but work very differently — and choosing the wrong one could create problems for the survivor.

What Is a Single Will?

A single will is a will made by one person. It covers that person's estate only — their assets, their beneficiaries, their executor, their wishes. Single wills are the most common type. Even within a couple, many people prefer to have individual wills rather than a shared document.

Best for:

• Individuals who aren't in a couple
• Couples whose estates and wishes are substantially different
• Anyone in a complex family situation (children from previous relationships, business assets, etc.)
• People who want full flexibility to change their will in the future without affecting their partner

WillSafe's single will kit covers everything you need to write your own legally valid individual will.

What Is a Mirror Will?

Mirror wills are two separate wills — one for each person in a couple — that reflect each other's wishes. The most common structure is: “I leave everything to my spouse/partner. If my spouse/partner dies before me, I leave everything to [our children / named beneficiaries].”

Each person signs their own separate document. They are independent wills that happen to have mirrored terms.

Key Facts About Mirror Wills

• They are separate, independent documents. Each person's will is their own and can be changed at any time.
• They are not binding on the survivor. After one partner dies, the surviving partner is free to write a new will and leave the estate to entirely different people.
• This is their main limitation for some couples. If you want to ensure the estate ultimately passes to your children, mirror wills alone don't guarantee this.

Best for: Couples with straightforward, shared wishes who trust each other to honour the spirit of their original arrangements.

WillSafe's mirror wills kit provides both wills together, with full guidance.

What Is a Joint Will?

A joint will is a single document signed by two people that covers both of their estates. It is the least commonly used of the three types — and for good reason.

A joint will sets out what happens when each person dies. It is signed by both parties and operates as a single document. Once one person dies, the will comes into effect for their estate and — in most interpretations — becomes irrevocable.

The Problem with Joint Wills

Joint wills are largely considered outdated and problematic in England and Wales:

1. They bind the survivor. Once one person has died under a joint will, the survivor may be unable to change the terms — even if their circumstances change dramatically.
2. They create legal uncertainty. There is ongoing debate about exactly how and when a joint will becomes irrevocable, which can lead to expensive litigation.
3. Most solicitors advise against them. The restrictions they impose on the survivor are rarely what couples actually want.

Best for: Almost no one in 2026. Mirror wills with a letter of wishes are a better solution.

Mirror Will vs Joint Will: The Key Difference

The bottom line: in almost all cases, mirror wills are preferable to a joint will for UK couples. They achieve the same goal while preserving flexibility for the survivor.

What About Mutual Wills?

Mutual wills are wills where both parties agree in a binding contract that neither will change the provisions after one dies. This is distinct from mirror wills, which carry no such obligation. Mutual wills are complex, legally risky, and rarely advisable. A solicitor's advice is strongly recommended before entering into mutual wills.

Which Type of Will Is Right for You?