It has been stated that measurement is the cash register in the exchange of natural gas. The natural gas business is based on the buying and selling of this commodity. Measurement is responsible for balancing the input (buying) and output (selling). Errors, on either side of this equation, affect the balance the entire business is based upon. Add the fact that natural gas measurement can be extremely complicated, auditing not only becomes desirable, but necessary. As it implies, auditing an electronic gas meter (EGM) requires careful examination of large amounts of data in order to verify volumes and to verify the cash register. An experienced auditor is the most valuable tool in this process. In order to maintain the scope of this paper, a general knowledge of natural gas measurement and EGM fundamentals will be assumed