Abstract: A tanker management system includes an integrated measurement unit that monitors liquid volumes managed by a tanker and records transfer volumes. The measurement unit has a tank interface that receives liquid level measurements for a tanker reservoir and a transfer interface that receives measurements for liquid transfers between the tanker reservoir and external liquid stores. The tanker management system has a control system that calculates the volume of liquid retained in the tanker reservoir, based on the received level measurements, and the volume of liquid exchanged with an external liquid store, based on the received measurements. The control system and measurement unit are an integrated unit within a unitary housing that includes an operator interface.