As under the UPA, the attribute of co-ownership distinguishes a partnership from a mere agency relationship. A business is a series of acts directed toward an end. Ownership involves the power of ultimate control. To state that partners are co-owners of a business is to state that they each have the power of ultimate control. See Official Comment to UPA § 6(1). On the other hand, as subsection (c)(1) makes clear, passive co- ownership of property by itself, as distinguished from the carrying on of a business, does not establish a partnership.

2. Subsection (b) provides that business associations organized under other statutes are not partnerships. Those statutory associations include corporations, limited partnerships, and limited liability companies. That continues the UPA concept that general partnership is the residual form of for profit business association, existing only if another form does not.

A limited partnership is not a partnership under this definition. Nevertheless, certain provisions of RUPA will continue to govern limited partnerships because RULPA itself, in Section 1105, so requires "in any case not provided for" in RULPA. For example, the rules applicable to a limited liability partnership will generally apply to limited partnerships. See Comment to Section 101(5) (definition of a limited liability partnership). In light of that RULPA Section 1105, UPA Section 6(2), which provides that limited partnerships are governed by the UPA, is redundant and has not been carried over to RUPA. It is also more appropriate that the applicability of RUPA to limited partnerships be governed exclusively by RULPA. For example, a RULPA amendment may clarify certain linkage questions regarding the application of the limited liability partnership rules to limited partnerships. See Comment to Section 101(5) for a suggested form of such an amendment.

It is not intended that RUPA change any common law rules concerning special types of associations, such as mining partnerships, which in some jurisdictions are not governed by the UPA.

Relationships that are called "joint ventures" are partnerships if they otherwise fit the definition of a partnership. An association is not classified as a partnership, however, simply because it is called a "joint venture."