In this writing a contextualization of services is made, by defining them as intangible compounds by actions, satisfactions, benefits and experiences, it is stated that these are difficult to measure because they lack objective attributes. For this, the structure of two instruments for measuring the quality of the audit service is compared; on the one hand, the Servqual, which is applied through two surveys composed of 22 questions each, in order to measure perceptions and expectations; The second, Servperf, does not consider the concept of expectation, reducing the number of questions in half, this model is considered appropriate because it handles perception as an approximation to customer satisfaction. These instruments are addressed from the requirements or requirements presented by the IQCS 1 international quality Control Standard, showing the key aspects within the provision of this type of services.