Nobody puts a sofa on a scale. A moving truck is weighed twice, empty and loaded, and the gap between the two is your shipment. Tare is the empty side of that subtraction, and getting it right is the difference between an honest invoice and an arguable one.
The subtraction
Federal rule 375.509(a) allows two methods. In the origin weigh, the mover finds the difference between the tare weight before loading and the gross weight of the same vehicle after loading. In the back weigh, it takes the gross weight with the shipment loaded and subtracts the tare after unloading. In both, the result is the net weight and the figure freight charges rest on.
The three conditions
Each condition removes something that would move the number: loose equipment, a driver's weight, a few hundred pounds of diesel. The scale must also be certified, which 375.103 defines as one inspected and certified by an authorized authority.
- The vehicle must carry all pads, dollies, hand trucks, ramps and other equipment needed for the shipment, at both weighings
- The driver and other persons must be off the vehicle during each weighing
- The fuel tanks must be full at each weighing, or, on an origin weigh, the mover must not add fuel between the two
The weight ticket
Each weighing produces a weight ticket, signed by the weigh master, and 375.519 requires the ticket to identify the entries as tare, gross or net. It also names the scale, the date, the vehicle, your last name and the bill of lading number. The freight bill must include true copies of all weight tickets. When you read yours, find the word tare on one line and gross on the other.
Your right to watch
Section 375.513 gives you the right to observe every weighing, and the mover must tell you where and when each one happens. If you choose not to watch, you are presumed to have waived that right for the weighing. After you are told the billing weight and charges, and before unloading begins on an origin-weighed shipment, you may demand a reweigh under 375.517. See reweigh.
Small shipments
For a shipment of 3,000 pounds or less, 375.511 permits a platform or warehouse certified scale before loading or after unloading instead of weighing the truck. If your load is that small, ask the estimator which method applies.