For couples · 5 min read
Mirror wills vs mutual wills: the difference matters
Two wills can look identical and still mean very different things. Here's the distinction that catches couples out, and the one we almost never recommend.
Published 6 October 2025 · The Velati Team
When two people make wills together — typically a married couple, civil partners or long-term cohabiting couple — they almost always want the wills to mirror each other: each leaves everything to the other, with the same backup beneficiaries (usually the children) if both have died. The wills are not joint documents; each person has their own. They simply happen to point in the same direction. These are 'mirror wills', and they are what most couples actually want.
Mirror wills: independent, revocable, ordinary
A mirror will is just an ordinary will that happens to mirror another. Either party can change theirs at any time without telling the other. After one of them dies, the survivor can rewrite their own will entirely if circumstances change — they remarry, the relationship with the children changes, they move country. Most couples find this flexibility appropriate. Velati's mirror-wills product is exactly this: two ordinary wills, drafted as a pair, priced as a pair, but legally independent.
Mutual wills: a binding promise that survives death
Mutual wills are different — and far less common. They are wills accompanied by a binding agreement between the two testators that neither will change their will without the other's consent during their joint lives, and that the survivor will not change theirs after the first dies. The agreement is enforced by the courts via a constructive trust over the survivor's estate. The survivor is, in effect, legally bound by the dead partner's wishes for the rest of their life.
Why mutual wills are rarely a good idea
The motivation is usually understandable: a parent wants to ensure that, if they die first, their share eventually reaches their own children rather than (say) a future second spouse of the surviving partner. The cost is enormous flexibility loss for the surviving partner, who may live for decades after the first death and whose circumstances may change profoundly. The constructive trust is also notoriously hard to interpret — the case law is messy, and the resulting disputes are bitter and expensive. Most private-client solicitors will steer you toward a life interest trust instead, which achieves the same goal more cleanly.
What we recommend instead
If your concern is making sure your half of the estate ultimately reaches your own children — typical for blended families — the right tool is usually a life interest trust written into a mirror will. Your share goes into trust on your death; the surviving partner has the right to live in the home and benefit from the income for life; on their death, the capital passes to the beneficiaries you originally chose. It is more flexible than mutual wills, easier to enforce, and the law is well settled. Velati's blended-family flow uses this structure as standard.
What to do if you genuinely want mutual wills
We don't currently offer mutual wills as a product. The risk of customers signing a binding lifelong agreement based on a self-serve questionnaire is too high. If after reading this you remain certain that mutual wills are right for your situation, please speak to a private-client solicitor who can take detailed instructions, explain the implications, and document the agreement properly.