QuickBooks for auto repair, where one margin hides four businesses.

Because they earn differently, and one blended margin tells you nothing about either. Labor is priced off a shop rate against technician cost; parts are priced off a markup against supplier cost. When both land in one service revenue account you can only read a combined gross margin, so parts pricing can erode for months while the overall number looks acceptable because labor is carrying it.

Sublet is work you send out to a specialist — machine shop, glass, alignment, towing, upholstery — and then bill to the customer. It needs its own revenue account and its own cost account, paired like parts and labor. Recorded that way, the sublet vendor's bill sits against the sublet you invoiced, and the margin on outsourced work is visible on its own rather than distorting your parts or labor numbers.

You can, and many shops do — a service item on the invoice at cost or with a markup is a perfectly ordinary way to bill it. The point is not how the customer sees it but where it lands: the amount you invoiced needs to hit sublet revenue and the vendor's bill needs to hit sublet cost. Whether you add margin is a pricing decision that belongs to you; whether the two sides are paired is the bookkeeping.

Treat it as its own revenue line with its own cost account. Rags, chemicals, fasteners, cleaner and the rest are consumed across many jobs and are usually recovered as a percentage on the ticket. Given a paired account, you can see whether what you charge for supplies actually covers what you spend on them — which is the whole reason the line exists and a question most shops cannot answer from a pooled file.

A core charge is a deposit on a returnable part, so it is not a cost of the job until it is clear the core is not going back. What makes cores difficult is the follow-through: the part goes back to the supplier and the credit is supposed to appear on a later statement, and QuickBooks has no way to notice that the credit never arrived. Tracking cores as an open item, and reconciling supplier credits against the returns that earned them, is the only thing that closes that loop.

It depends on how you buy. A shop that orders per job and fits the part the same week is running parts as a direct cost, and full inventory tracking adds counting work for very little return. A shop that stocks fast-movers, filters, fluids and tires has a genuine inventory asset that needs to be valued and counted. The free review is where we tell you which you are, including when the honest answer is that you do not need inventory turned on.

Yes, and most shops we work with are in that position. The management system runs the ticket and QuickBooks holds the accounting. What matters is how the day's or the ticket's totals arrive in QuickBooks: they need to land split by revenue line, not as one lump. We do not assert what any particular system exports, because those change — we work from what yours actually produces and map it to the right accounts.

No. Your shop rate, your parts markup and your supply percentage are commercial decisions that depend on your market, your technicians and your competition. What we do is make the results of those decisions visible, line by line, so you can see what each is actually returning rather than guessing from one combined figure.

Yes, and the catch-up can come first. Repair shops fall behind because ticket volume is high and parts invoices arrive constantly from several suppliers. A catch-up splits the historical revenue back into its lines where the records support it, matches supplier bills to the jobs they belonged to, and rebuilds a margin you can actually read.

No. We keep the books — the paired revenue and cost lines, the sublet, the core and credit tracking — so the file is accurate and current. Your CPA sets tax positions, advises on inventory method, and files returns. Good bookkeeping makes that work faster; it does not replace it.