Mirror wills vs single wills: which do we need?

What is a single will?

A single will is exactly what it sounds like — one will, for one person. It sets out who inherits your estate, who looks after any children, and who acts as your executor. Anyone over 18 can make one, whether you're single, married, cohabiting or separated.

What is a mirror will?

Mirror wills are two separate wills, written for a couple, where each will "mirrors" the other. Typically, you each leave everything to your partner first, and then to the same chosen beneficiaries — usually your children — when the second of you dies. The executors and guardians are normally the same in both documents.

Mirror wills are still two distinct legal documents. Either of you can change yours at any time, including after the other has died.

When mirror wills make sense

• You're married, in a civil partnership or living together long-term.
• You broadly agree on who should inherit and who should be guardian to your children.
• You want the simpler, cheaper option — two wills are usually priced as a pair.
• Your finances are mostly shared and your family situation is straightforward.

When a single will is the better fit

• You're not in a relationship, or you'd rather plan independently.
• You and your partner want noticeably different things — different beneficiaries, different executors, or unequal shares.
• One of you has children from a previous relationship and you need tailored protection for them (often using a trust).
• You have business interests, overseas assets or other complexity that doesn't mirror your partner's situation.

The honest limitation of mirror wills

Mirror wills are not binding on the survivor. After the first death, the surviving partner is free to rewrite their will, remarry, or leave the estate elsewhere — which can unintentionally cut out children from a previous relationship. If that's a concern, a mirror will alone isn't enough. We'd usually look at a property protection trust or life interest trust alongside the wills.

So which do you need?

For most couples with a shared life and shared intentions, mirror wills are the sensible, cost-effective choice. For blended families, unmarried partners with different wishes, or anyone with more complex assets, single wills — often paired with a trust — give you the control you actually need.

The good news: you don't have to work it out on your own. A short conversation is usually enough to know which route fits.