What document formalizes ownership of a unit in a cooperative?

In a cooperative housing arrangement, ownership is structured differently than traditional real estate ownership. Instead of owning the property directly, residents are shareholders in the cooperative corporation that owns the property. This means that the document that formalizes ownership in a cooperative is a share certificate.

A share certificate serves as proof that an individual holds shares in the cooperative and, consequently, has an interest in the property managed by that cooperative. It details the number of shares owned and ensures that the holder has the rights to occupy a unit and participate in the cooperative's governance.

In contrast, other documents like a lease agreement would primarily outline the terms of occupancy without conveying ownership, while a title deed is associated with ownership of real estate rather than shares in a cooperative. A certificate of ownership might suggest ownership, but in the case of cooperatives, it is the share certificate that correctly represents the ownership structure.