The welfare exemption is jointly administered by the Board of Equalization (BOE) and the San Francisco Assessor-Recorders Office.
BOE determines whether the organization is eligible to receive the exemption and the Assessor determines whether the use of the property is eligible for the exemption. Before the Assessor can approve the exemption, the organization must apply for and BOE must issue an Organization Clearance Certificate. Property owned by a limited partnership must also obtain a Supplemental Clearance Certificate from the BOE.
Organizations filing for the first time in the state are required to provide an Organizational Clearance Certificate (Supplemental Clearance Certificate for Managing General Partner if organization is a LP) and organizational documents (articles of incorporation and other formative documents, tax exemption letters, financial statements, etc.).
Leased property is not eligible for the exemption unless both the owner and the operator file and qualify for the exemption. If the owner of real property does not qualify for the exemption, a qualified operator may still receive the exemption on the personal property it owns.
Some reasons may be no exempt activity on lien date (January 1st), rental properties, vacant or unused land/space, for-profit groups using property; etc.
Source URL: http://sfassessor.org/tax-savings/exemptions/non-profit-exemption