Why parts on a workshop invoice do not leave stock
Why parts typed onto a workshop invoice stay in Achekam's stock, how selling them through the till fixes it, and how to check stock after a busy week.
By Achekam · · 4 min read · For Automotive businesses in South Africa, Nigeria, Kenya
The service is done. The adviser opens a new invoice and types it out: an oil filter, engine oil, a set of wiper blades, and the labour. The customer pays and drives away. At month end the parts manager counts the shelf and finds the stock list still thinks the filter and the blades are there.
Nothing is broken. A typed invoice line simply is not a stock movement in Achekam. Once a workshop knows that, it can arrange its counter so that parts leave stock when they leave the building. This article explains why it happens and the split that keeps stock right.
Typed invoice lines and what they post
Customer invoices are built from typed lines. A line cannot be picked from the business's product list, so the invoice has no idea that "oil filter" is the same thing as the oil filter in your Item Master. Because of that, invoices do not move stock and do not post cost of sales.
They also all post to one revenue account, Professional Services Revenue (4100), and a line cannot name another sales account. So a parts line on an invoice is recorded as service income, with no cost beside it, and the part stays on the stock list.
The till takes parts off stock; the invoice does not
The till behaves differently. A till sale takes the sold quantity off stock in the same step, at the till's own location, and refuses to go below nil unless the business allows negative stock. The same sale posts a balanced journal: the payment to its own account, revenue, output VAT, and cost of sales against inventory at the product's cost price.
In short:
| Invoice line | Till sale | |
|---|---|---|
| Picks the product from your list | No, typed | Yes |
| Takes the part off stock | No | Yes, at the till's location |
| Posts cost of sales | No | Yes, at the item's cost price |
| Revenue account | 4100 | 4000 |
Selling parts at the till on the customer's account
The obvious worry is the customer who does not pay on the day: the fleet operator, the taxi owner with several vehicles, the dealer down the road. The till refuses a sale that is not paid in full, but it can charge a sale to a trade customer's account.
Charging to account writes a receivables invoice for that customer and checks the account's hold and credit limit, unless a supervisor or manager overrides it with a reason. The parts still leave stock and still post cost of sales, because it is still a till sale. Trade customers are created on the Wholesale screen, which needs the Wholesale add-on. Manufacturers who run a trade counter use the same mechanism; a trade counter on account walks through it from their side.
Labour on the invoice, parts through the till: a split that works
For most workshops the cleanest routine is:
- Parts are rung up at the till against the job, paid on collection or charged to the customer's account.
- Labour goes on a customer invoice, typed as usual.
- The customer receives the till receipt or account invoice for parts, and the labour invoice, and you file both with the job card.
A worked example in words: a fleet customer's van comes in for a service. The adviser rings up the filter, oil and brake pads at the till and charges them to the fleet's account. The labour goes on an invoice to the same fleet. At month end the fleet's statement shows both, the parts have left stock, and your income statement shows parts revenue with its cost in one place and labour in another. That separation is what lets you read your parts margin, as seeing parts margin apart from labour explains.
The one discipline it needs: nobody types a part onto a labour invoice "just this once". Make it a rule at the service desk.
Checking stock after a busy week
Even with the split in place, check. A missed scan, a part taken for a comeback job, or a box opened for one bolt will put the shelf and the list apart.
With the Warehousing add-on, Achekam keeps stock locations, such as the main store, a workshop bin or a service van, with the quantity on hand at each. A stock count sets a location's quantity to what was counted and records the difference as an adjustment.
Two points to keep in mind:
- Stock counts, wastage and transfers do not post to the general ledger; only till sales and till returns move the inventory account. When a count finds a difference, tell your accountant so it can be put through the books.
- Counting everything once a year finds problems too late. Many workshops count a few fast-moving lines every week instead. AccountingTools explains cycle counting, counting a small part of inventory every day so the whole stock is counted over time instead of in one annual count.
A short Friday list:
- count the top fast movers: filters, oil, brake pads, wiper blades, bulbs;
- compare with the stock quantity and note every difference;
- look for parts typed on invoices that week and ring them through the till if they were not;
- pass the differences to whoever keeps the books.
Getting the counter right
Set up your parts in the Item Master with clear SKUs, which parts stock, SKUs and barcodes covers, and then brief every adviser and counter hand on the split above. Run it for a month and count the same lines at the end; the gap between shelf and list should close.
General guidance only, not advice on your own circumstances. Tax and payroll rules change: check the current position with the authority or your adviser.
