Heavy duty and diesel truck shops differ from car shops less in the wrenching and more in who is paying and what they need documented. The customer is usually a motor carrier rather than a driver, the vehicle is usually part of a fleet with its own compliance obligations, and the repair record is not just yours: it feeds a maintenance file the carrier is required to keep. That changes what your software has to produce. This page covers the paperwork the customer needs from you, the periodic inspection that drives a chunk of the work, and how fleet billing differs from counter billing.
Your invoice feeds somebody else's compliance file
A motor carrier must keep, for each vehicle it controls, a record of inspections, repairs and maintenance showing their date and nature, and those records are retained where the vehicle is housed or maintained for one year and for six months after the vehicle leaves the carrier's control (49 CFR 396.3). Your repair order is a source document for that file. Writing it so the date, the vehicle, the work and the parts are unambiguous is not administrative politeness; it is the thing that makes your invoice usable to the customer who is legally on the hook.
The annual inspection is real, recurring work
Every commercial motor vehicle must be inspected as required by the periodic inspection rule, covering at minimum the parts and accessories set out in the appendix to that part (49 CFR 396.17). For a shop with fleet customers that is a predictable, schedulable body of work, and a shop that tracks when each customer vehicle is due has a reason to call that is useful rather than promotional. Software that can hold a next due date per customer vehicle turns that into a booked calendar.
Fleet billing is not counter billing
A fleet customer wants a purchase order number on the invoice, work authorized against a standing agreement rather than a phone call, consolidated billing across many units, and a unit number as well as a plate. Counter oriented software handles none of that gracefully. If fleet work is more than an occasional job for you, make any vendor show you a month end consolidated invoice across fifteen units with PO numbers on it, on their data, before you buy.
Downtime is the customer's real cost
A truck off the road costs a carrier far more per day than the repair, which changes what good service means: an honest completion estimate beats an optimistic one, and a status update beats silence. It also changes what your record has to show, because a carrier reconciling downtime wants dates in and out on the invoice. That is a small field with a large effect on whether a fleet keeps coming back.
Questions people ask about heavy duty shop management software
Do we have to keep the maintenance records, or does the carrier?
The carrier carries the obligation for its own vehicles under 49 CFR 396.3, and your records are what it builds that file from. Keep your own copies for your own tax and warranty purposes, and make sure what you hand over is complete enough to be used.
Is a car shop system usable for heavy duty?
For the wrenching, mostly. It will strain on unit numbers, purchase orders, consolidated fleet billing and anything to do with periodic inspections, and those are exactly the parts your fleet customers judge you on.
What should a fleet invoice show that a retail one does not?
The unit number, the purchase order, the dates in and out, and the work broken down so a maintenance file can absorb it. Everything else is the same document you already write.