If tax has been paid on any article or tangible personal property in any other state or political subdivision thereof in respect to its sale or use in an amount less than the tax imposed by this chapter, the provisions of this chapter apply, but in an amount equal to the difference between the tax imposed by this chapter and the tax paid in the other state or political subdivision thereof. If the tax paid in the other state or political subdivision thereof is the same or more, then no tax is due on such article. The provisions of this section apply only if such other state or political subdivision thereof allows a tax credit with respect to the retail sales and use taxes imposed by this state which is substantially similar in effect to the credit allowed by this section. The tax commissioner may require the taxpayer to provide written proof from the other state or political subdivision that the tax was legally due and paid.
N.D.C.C. § 57-40.2-11