How postings affect costs
Every time you post labor, parts, tires, a miscellaneous charge, or an outside/warranty variant of one of those to a job, you are adding a priced entry to that job's transaction record. This article explains how that single entry turns into the dollar figures you see elsewhere on the Work Order — the job's own subtotal, the category breakdown on the Work Order's cost cards, and the one Total cost figure on the Work Order summary. It's written for anyone reading or reconciling the cost on a Work Order — not just the person doing the posting — since the totals it describes are visible to reviewers and approvers as well as to whoever posted the transaction. It does not explain how to perform a posting; see Related tasks below, and see Posting types and Transaction types for what each posting records at the field level.
A posting is a price and a quantity
Whatever you post — an hour of labor, a part taken from a bin, a tire mounted, a miscellaneous charge — the transaction that results carries a price and a quantity. Price times quantity is the amount that transaction contributes to the job's cost. Post two hours of labor at a given rate, and that transaction contributes two times that rate. Post three of the same part, and that transaction contributes three times the unit price. This is the same underlying shape for every posting type described in Posting types — only the fields that go into the price and quantity differ (a labor rate and hours, a part's unit price and count, and so on).
Every transaction also carries a separate internal cost figure alongside its price — see Transaction types for that field-level distinction. The concept in this article is about price: what a transaction contributes to the job and Work Order cost totals you see on screen is driven by price × quantity, not by the internal cost figure.
Transactions build up into a job subtotal
A job's transactions are grouped into categories — Labor, Parts, Tires, and Misc — and each category's amount is the sum of price × quantity across the transactions posted to that job under that category. Outside and Warranty postings aren't a fifth and sixth category of their own at the job level; an Outside Labor posting adds to the same Labor bucket a regular Labor posting would, and a Warranty Parts posting adds to the same Parts bucket, because they represent the same kind of work performed under a different billing arrangement. The four category amounts add up to the job's Subtotal, shown when you expand a job's transaction list.
This means a job's Subtotal always reflects exactly what has been posted to it, and only what has been posted to it — reversing a transaction (see Transaction types) removes its contribution from the subtotal because a reversal creates an offsetting entry rather than deleting the original.
A job's transaction list also shows a "Total" figure in its collapsed row that is not always guaranteed to match the expanded Subtotal exactly. If you notice the two disagreeing on cost — as opposed to a difference in quantity or missing charges — that's a display point to raise with support rather than something to troubleshoot yourself; it isn't covered by the ordinary posting-and-cost concept described here.
Job subtotals build up into the Work Order total
The Work Order's cost cards present the same category groupings at the Work Order level — across every job on the Work Order — split further into In House and Outside where that distinction applies (Parts, Labor, and Tires each show an In House row and an Outside row; Warranty combines its labor, parts, and tire postings into a single figure; Other covers Miscellaneous charges and, separately, a Damage figure that is shown for visibility but isn't folded into the Other total, since it can overlap with charges already counted elsewhere). Together, these category figures are what add up to the single Total cost shown on the Work Order summary.
Because postings can happen from any job on the Work Order at any time, the Work Order's totals are re-fetched every time a posting is made, rather than computed by adding up whatever job subtotals happen to be showing on screen. In practice this means the Total cost on the Work Order summary should always reflect the most recently posted transaction across every job, without needing to reopen or refresh the Work Order — post a transaction to any job, and the Work Order-level totals update to include it.
Why this distinction matters
Understanding that a Work Order's cost is a live rollup — transaction → job subtotal by category → Work Order total — rather than a number set once, explains a few things you'll observe in practice:
The Work Order's Total cost can change after the Work Order itself was created or even marked ready for review, if a job on it is reopened and a new posting is made.
Reversing a transaction affects the job subtotal and the Work Order total the same way posting one does, just in the opposite direction — because a reversal is itself a transaction, not a deletion.
The In House / Outside split and the Warranty rollup on the Work Order's cost cards exist because those distinctions matter for how the Work Order is billed or reconciled, even though at the job level an Outside or Warranty posting is just another entry in its ordinary category (Labor, Parts, or Tires).