What is a income partner?

For some information about a partnership go to the IRS gov web site and use the search box for Publication 541 go to chapter Forming a Partnership

An unincorporated organization with two or more members is generally classified as a partnership for federal tax purposes if its members carry on a trade, business, financial operation, or venture and divide its profits. However, a joint undertaking merely to share expenses is not a partnership. For example, co-ownership of property maintained and rented or leased is not a partnership unless the co-owners provide services to the tenants.

The rules you must use to determine whether an organization is classified as a partnership changed for organizations formed after 1996.Organizations formed after 1996. An organization formed after 1996 is classified as a partnership for federal tax purposes if it has two or more members and it is none of the following.