What is the chassis per-diem audit?

Pools bill a daily charge once a chassis is out past its free days, and their invoices arrive weeks later. Chassis & per-diem (in the Track & Trace account menu, part of Track & Trace Pro) keeps your own ledger: log each out-gate, and cost accrues by port-local business day using your pool's rate card, free days and tiers. Drivers close the clock from the app — after delivery, tap Chassis returned on the trip. Import the pool's invoice and the audit flags overbilled days, wrong tiers and duplicates so you can dispute them with evidence.