In Arizona, property law is governed by ARS Title 33. Joint tenancy with right of survivorship is covered in ARS 33-431. When real property is owned by multiple people, property law refers to it as a concurrent estate.
Joint tenancy is most common among married couples because it helps property owners avoid probate. Without joint tenancy, a spouse would have to wait for their partner's Last Will to go through a legal review process—which can take months or even years.
For example, if two unmarried partners make equal contributions toward purchasing a inium and they choose to hold title as joint tenants, the surviving joint tenant will automatically become the sole and separate owner of the inium after the first joint tenant dies.
Joint tenancy is most common among married couples because it helps property owners avoid probate. Without joint tenancy, a spouse would have to wait for their partner's Last Will to go through a legal review process—which can take months or even years.
In the context of joint tenancy, typically four unities are required for its valid creation: Unity of Possession, Unity of Interest, Unity of Time, and Unity of Title, collectively referred to as the 'four unities' in property law. However, one example of a 'unity' that is not required is the Unity of Marriage.
Further tenancy in common allows parties to hold unequal shares of property interest. Joint tenancy requires each co-owner to hold equal shares of property. Further, co-owners must transfer the deed at the same time. In this sense, joint tenancy is rigid compared to tenancy in common.