Formalities

• A few states, such as California, make tenancy-in-common the default ownership interest when a seller conveys property to multiple individuals. However, in most states, the default interest is a joint tenancy, and the law requires certain formalities in order to create a tenancy-in-common. The document conveying the property must specify a tenancy-in-common by stating "To A and B as tenants-in-common."
  
  

Lack of Survivorship

• Some concurrent estates have a right of survivorship, meaning that if one of the tenants dies, his interest is effectively extinguished. He does not have a share of the property to pass on by will or inheritance; rather, the other tenants will now be the only ones with rights to the property. In a tenancy-in-common, however, if one of the tenants dies, his proportional interest (for instance, 1/3 if he was one of three tenants) will be severed from the whole and can pass on via will or inheritance.
  
  

Unity of Possession

• Tenants-in-common share an undivided interest in the property; in comparison to a joint tenancy, each tenant does not own the whole property. Each tenant owns a proportional interest, a fraction of the property which he is free to will away, pass to descendants upon death or sell to another party. However, all tenants in common share a unity of possession, which means that each individual tenant has the right to possess the entire property. For instance, if three tenants own a property in common, one of them may come and live on and use the entirety of the land in any manner he likes, and may keep any profit he reaps from such use the property.
  
  

Contribution Rights

• Courts of equity may allow one co-tenant to demand that the other tenants contribute certain assistance for the upkeep of the property. The majority of jurisdictions allow one co-tenant to compel the others to contribute to the cost of repairs, so long as that co-tenant gives the others adequate notice of the need for repairs. Courts will also generally allow one tenant to demand that the others pay their fair share of mortgage payments and taxes, based on the fair value of the property. However, if one co-tenant makes improvements (rather than repairs) to the property, he has no right to contribution from the other co-tenants unless he brings an action in partition. Partition effectively severs ownership of the property and entitles the improving co-tenant to a contribution equal to the the increase in property value.
  
  

Ouster

• Although each co-tenant has the right to possess the entire property, no one co-tenant can possess the property and exclude other co-tenants who wish to use it also. Should one co-tenant attempt to exclude the others from the property, the other co-tenants have been effectively "ousted" from the property. They may then bring an action in court to compel the tenant in possession of the property to pay them the fair rental value of the property from which they were excluded for the relevant time period.