The TNMM focuses on the net operating profit margin and tests the arm's length character of transfer prices in a controlled transaction by comparing the operating profit margin earned by one of the parties engaged in the controlled transaction to the operating profit margins earned by uncontrolled parties
engaged in similar business activities.
Comparability under the TNMM is dependent primarily on the similarity of
capital invested and risks assumed by the controlled and uncontrolled parties
with respect to such activities.
The degree of functional comparability required to obtain a reliable result under the TNMM is generally less than that required under the RPM and the CP Method.