Administratum

The Administratum is the name of the pencil pushers of the Imperium of Man. Founded by Malcador the Sigilate back in the day the Emprah was strutting about, the Administratum is the bureaucratic division of the Adeptus Terra. They assess the tithes every world must pay to the Imperium, take census data, and maintain records. Imagine the Department of Motor Vehicles with all the grimdark of Warhammer 40,000. The Adepts of a department will keep going about their duties long after their department has become completely useless. That's the Administratum. It's run by the aptly named Master of the Administratum, who is the most powerful of the High Lords of Terra.