The linehaul rate pays for moving the freight from A to B. Accessorials pay for everything else the load turns out to require. Some are predictable and priced in advance (a second stop, a tarp on a flatbed load); others are triggered by what happens on the day (detention, redelivery after a missed appointment).
Accessorials are where a load’s real margin is won or lost. A load booked at a thin linehaul rate can still be profitable if the stop-off, tarp, and detention are all billed and collected — and a load booked at a strong rate can lose money if those charges are absorbed.
Every accessorial should be defined on the rate confirmation: what it is, how much, and what documentation the payer requires. Charges added after the fact without prior agreement are the ones that get short-paid.
Example
A flatbed load is booked at $2.10 per mile linehaul, plus $150 for tarping and $75 per additional stop. The load has one extra stop and requires tarping, so $225 in accessorials is added to the linehaul on the invoice — all pre-agreed on the rate confirmation, so all collected without dispute.
Why it matters
Carriers that track and bill accessorials line-by-line collect noticeably more per load than carriers that only invoice the linehaul rate and let the extras slide.
In Trailflow, this shows up in invoicing and settlements.