Sales Other Than Sales Of Tangible Personalty Within State - Mich. Comp. Laws Section 206.123

Sec. 123.

Sales, other than sales of tangible personal property, are in this state if:

(a) The income-producing activity is performed in this state; or

(b) The income-producing activity is performed both in and outside this state and a greater proportion of the income-producing activity is performed in this state than outside this state, based on costs of performance.