The Substantial Presence Test (SPT) is a criterion used by the Internal Revenue Service (IRS) in the United States to determine whether an individual who is not a citizen or lawful permanent resident in the recent past qualifies as a "resident for tax purposes" or a "nonresident for tax purposes"; it is a form of physical presence test. The SPT should be used in conjunction with the Green Card Test (the criterion that the individual possessed a valid Green Card at any time of the year). An individual who satisfies either one or both of these tests is treated as a resident for tax purposes.