It depends. The Internal Revenue Service calls office space donations in-kind
donations. The IRS encourages in-kind donations by allowing individuals
and businesses to take a tax deduction for the fair market value of the
service. For office space, this is sale price of the space if it were
placed on the market or the fair market value of a lease. The recipient
must be a tax-exempt charitable organization or 501(c)(3). IRS rules do
not allow donations for a portion of the owner's interest in a property.
For example, if you own a multi-story building and allow a nonprofit to
occupy one of the floors for free, you cannot take a deduction. The
reasoning is that because you still own the building, you have lost no
benefit of ownership.
