A Mirror Will is what most couples sign. Each spouse signs a separate will. The contents are reciprocal — each leaves everything to the other, and then to the same children or beneficiaries on the death of the second spouse ². Each spouse can update or revoke their own Mirror Will at any time, including after the other dies.

A Mutual Will goes further. Two wills are signed with a binding agreement between the spouses not to revoke after the first death. Once one spouse dies, the survivor is contractually bound to the agreed distribution. Mutual Wills are rare in Singapore practice and carry significant legal complications — courts have interpreted them as creating constructive trusts that restrict the survivor’s freedom over assets they later acquire ². Most couples don’t need this — and many couples who think they want it end up wanting a Mirror Will instead, with a trust structure for specific concerns.

Both types must still comply with the Wills Act 1838 — written, signed at the foot, witnessed by two people present together, neither of whom is a beneficiary or spouse of a beneficiary ¹. Each spouse signs their own will separately, with their own witnesses.

One more thing every couple should know. Under section 13 of the Wills Act, marriage automatically revokes any will made before the marriage — unless the will was expressly made “in contemplation of marriage” to a specific person ¹. If you wrote a will before you got married and never updated it, you’re effectively intestate.