What type of ownership allows a co-owner to leave their share to a third party in their will?

The type of ownership that allows a co-owner to leave their share to a third party in their will is tenancy in common. This form of ownership provides each co-owner with an individual, undivided interest in the property. Each co-owner can freely transfer their interest, whether by selling it or through a will upon their death. This means that if one co-owner wishes to bequeath their share to someone else, they have the legal right to do so, and that person's interest will then become a part of the new owner’s estate.

In contrast, joint tenancy entails that co-owners share ownership equally and have a right of survivorship, which means that when one owner dies, their share automatically passes to the surviving joint tenants, not to any heirs or beneficiaries named in a will. This key difference makes tenancy in common suitable for individuals seeking the ability to allocate their interest in the property according to their wishes after death.

The other options, such as life interest or shared tenancy, do not typically offer the same flexibility regarding legacy and transferability of ownership as tenancy in common does.