Joint Tenancy vs Tenancy in Common

Joint tenancy and tenancy in common are the two principal forms of concurrent ownership of real property. The fundamental distinction is the right of survivorship: in a joint tenancy, when one joint tenant dies, that tenant's interest automatically passes to the surviving joint tenant(s) by operation of law, outside of probate. In a tenancy in common, each tenant holds a separate, undivided interest that passes to the tenant's heirs or devisees upon death.

At common law, creating a joint tenancy required the four unities: time (all interests must vest at the same time), title (all interests must arise from the same instrument), interest (all tenants must hold equal shares of the same type of estate), and possession (all tenants must have equal rights to possess the whole property). If any unity was lacking, the estate was a tenancy in common. Modern law presumes a tenancy in common in most jurisdictions, and creating a joint tenancy requires clear and express language indicating the intent to create a right of survivorship.

A joint tenancy can be severed (converted to a tenancy in common) by any joint tenant's unilateral action, such as conveying the interest to a third party, executing a mortgage (in title theory states), or obtaining a judicial partition. Severance destroys the right of survivorship. A tenancy in common, by contrast, cannot be 'severed' because there is no survivorship right to destroy. Both joint tenants and tenants in common have the right to partition -- the division of the property either physically (partition in kind) or through a forced sale (partition by sale).