If your home has a newer water meter installed with an outside remote that is a solid black oval disc, there is no need to compare inside and outside readings. The communication between the remote and the meter is done electronically. If there is a problem with the communication from the meter to the remote, an error code is sent to the electronic reading device. A meter checkup will be scheduled to determine the cause of the difference.
At least annually, you should compare the register reading on the meter with that on the outside register (as shown in the diagram). Any discrepancy over 3,000 gallons should be reported to the Finance Department at 630-271-4131.