Garage Stock Management: A Practical Guide to Parts

For an independent garage, parts are one of the biggest costs, and they are also the easiest place to lose money without noticing. A filter fitted but never billed, a box of pads counted twice, a supplier delivery that never reached the records: each one is small, but together they decide whether the month ends in profit. This guide explains how to set up parts stock so the figures on screen match what is on the shelf.

Why garage stock goes wrong

Stock records rarely fail all at once. They drift, usually for the same few reasons:

• Parts are taken from the shelf for a job, but the job card is written up later, or not at all.
• Deliveries are unpacked straight onto the shelf and the supplier invoice goes into a drawer.
• The same part exists under three names, so nobody trusts the quantity of any of them.
• Nobody counts, so errors from last year are still in this year’s figures.
• Reordering depends on someone noticing an empty box.

The fix is not more paperwork. It is a small number of rules that everyone follows, backed by a system that does the arithmetic for you.

Start with a clean product card

Every part you keep should have exactly one product card. Duplicates are the main reason stock figures stop being believable, so search before you create. A useful product card holds:

• Name: written the same way every time, for example “Brake pads, front, Corolla 2019–2022” rather than “pads”.
• SKU and OEM number: your own stock code plus the manufacturer’s part number, which is what you order and cross-reference against.
• Barcode: the supplier’s barcode where there is one.
• Brand, category and unit: categories such as filters, brakes and oils make counting and reporting far easier. The unit matters for oil and fluids sold by the litre.
• Shelf location: a short code such as “B3-2”. It saves time when picking and during counts.
• Purchase price, sale price and tax rate.
• Minimum stock level: the quantity at which you want to be warned.

Labour and services, such as a wheel alignment, should be set up as services rather than stock items, so they never show a quantity on hand. Consumables you do not want to track piece by piece, like cable ties, can have stock tracking switched off.

Barcodes and labels

Barcodes remove the two most common causes of error: picking the wrong product card and mistyping a quantity. Where a part arrives with a manufacturer barcode, record it on the product card. Where it does not, print your own labels with the product name and a barcode, and stick them on the box or the shelf edge. With labels in place you can scan a part at the counter for a quick sale and scan shelf by shelf during a stock count, using a scanner at the desk or the camera of a phone on the shop floor.

Booking in deliveries with purchase invoices

Every delivery should be booked in against the supplier’s invoice before the parts go on the shelf. Record the supplier, the invoice number and date, and each line with its quantity and purchase price. That single step increases stock, gives you a record of what each part cost and tells you later which supplier you last bought it from. If a delivery is short or damaged, book in what actually arrived, not what the invoice says, and settle the difference with the supplier.

If you run more than one site, book the delivery in at the branch that physically received it, so the stock appears where the parts really are.

Automatic deduction from job cards and sales

The rule that makes everything else work is simple: no part leaves the shelf without a line on a job card or a sale. If the stock system is connected to your job cards, you do not need a separate issue note. In Baktam, adding a part to a job card or a counter sale deducts it from the stock of that branch straight away, labour lines never touch stock, and cancelling the job card puts the parts back. If a branch does not have enough of a tracked part, the line is refused rather than letting the quantity go below zero, which is a useful early warning that a delivery was never booked in.

Because the deduction happens when the line is added, an estimate that includes parts reserves them too. If a customer declines, cancel the job card so the parts return to stock.

Stock counts that people actually finish

A full count once a year is better than nothing, but small regular counts are easier to finish and catch problems while they are still fresh. A workable routine:

1. Count one category at a time, for example filters this week and brake parts next week.
2. Start the count in the system so it records the expected quantity for each item at that moment.
3. Walk the shelves in location order and enter or scan what is actually there.
4. Review the variances before applying them: a large difference is often a missing delivery or a wrong product card, not theft.
5. Apply the count, so the stock is corrected and the adjustment is recorded.

Try not to move parts during a count. If you must, finish the job card first so the deduction is already in the expected figures.

Low-stock alerts and reordering

Set a minimum level on the parts you cannot afford to run out of, such as popular filters, pads, bulbs and the oils you use every day. When stock falls to that level, the owner should hear about it. Baktam sends a low-stock notification when an item crosses its minimum and keeps a reorder suggestion list showing each low item with its current stock, its usage over the last 30 days, a suggested quantity and the supplier you last bought it from. The list can be exported to CSV and sent to your parts supplier as an order.

Review minimum levels every few months. A level that made sense in winter may be too low when air conditioning jobs pick up in summer.

Several branches: transfers between sites

With two or more sites, each branch needs its own stock figure: a part in the main warehouse is no help to a customer waiting at another branch. Moving parts between sites should be a transfer, not a deduction at one site and a manual addition at the other. A good transfer has three stages: prepared, sent and received. Stock leaves the sending branch when the transfer is sent and arrives at the other branch only when someone there confirms receipt, so parts in transit are never counted twice. Our garage management software page explains how branches, stock and job cards fit together.

Mistakes to avoid

• Creating a new product card when a search would have found the old one.
• Correcting stock by hand instead of finding the missing job card or invoice. A manual adjustment hides the real problem.
• Letting technicians take parts “for now”. If a part is needed, it goes on the job card at that moment.
• Setting every minimum level to zero. Then alerts never fire and reordering is back to guesswork.
• Counting everything at once, once a year. Smaller, regular counts are more accurate.

None of this needs a large team. A clean product list, deliveries booked in on arrival, parts always on a job card and a short count every week will keep your stock figures honest.