The bill forms shall show: Amount. The gross or net amount, or both, of the bill. Payment Date. The date by which the customer must pay the bill in order to benefit from a discount or to avoid a penalty. Estimated Bill. A distinct marking to identify an estimated bill. Rate Schedule. The applicable rate schedule, or identification of the applicable rate schedule. If the actual rates are not shown, the bill shall carry a statement to the effect that the applicable rate schedule will be furnished on request. Metering Data. If the rate for sewerage service is based on the reading of the water meter, the bill forms shall show: Meter Reading. The reading of the meter at the end of the period for which the bill is rendered. Meter Reading Date. The date on which the meter was read. Units Used. The number and kind of units metered.