Concurrent estate

In property law, a concurrent estate or co-tenancy is any of various ways in which property is owned by more than one person at a time. If more than one person owns the same property, they are commonly referred to as co-owners. Legal terminology for co-owners of real estate is either co-tenants or joint tenants, with the latter phrase signifying a right of survivorship. Most common law jurisdictions recognize tenancies in common and joint tenancies.

Many jurisdictions also recognize tenancies by the entirety, which is effectively a joint tenancy between married persons. Many jurisdictions refer to a joint tenancy as a joint tenancy with right of survivorship, but they are the same, as every joint tenancy includes a right of survivorship. In contrast, a tenancy in common does not include a right of survivorship.

The type of co-ownership does not affect the right of co-owners to sell their fractional interest in the property to others during their lifetimes, but it does affect their power to will the property upon death to their devisees in the case of joint tenants. However, any joint tenant can change this by severing the joint tenancy. This occurs whenever a joint tenant transfers their fractional interest in the property.

Laws can vary from place to place, and the following general discussion will not be applicable in its entirety to all jurisdictions.

Under the common law, Co-owners share a number of rights by default:

Co-owners generally do not have any obligation to contribute to any costs of improving the property. If one co-owner adds a feature that enhances the value of the property, that co-owner has no right to demand that any others share the cost of adding that feature – even if other co-owners reap greater profits from the property because of it. However, at partition, a co-owner is entitled to recover the value added by their improvements of the property if the "improvements" resulted in an increase in property value. Conversely, if the co-owner's "improvements" decrease the value of the property, the co-owner is responsible for the decrease. In an Australian case, the High Court said that the costs of repairing by one co-owner must be taken into account on the partition or final distribution (i.e. sale) of the property.

Each co-owner can independently encumber the co-owner's own share in the property by taking out a mortgage using fractional financing on that share (although this may effectively convert a joint tenancy to a tenancy in common, as described below); other co-owners have no obligation to help pay a mortgage that only runs to another owner's share of the property, and the mortgagee can only foreclose on that mortgagor's share. Bank loans secured by mortgages on individual shares of co-owned property are one of the most rapidly expanding areas in the mortgage lending industry.

Tenancy in common (TIC) is a form of concurrent estate in which each owner, referred to as a tenant in common, is regarded by the law as owning separate and distinct shares of the same property. By default, all co-owners own equal shares, but their interests may differ in size.