Auto repair shops: parts and labour on one invoice
One job, two different things sold: the part you fitted and the work you did. Here is why your invoice should show both.
A customer brings in a car. You diagnose it, order a part, fit it, and hand back the keys with one number at the bottom of the page.
Behind that number are two different transactions: you sold goods, and you provided a service. Most workshops write one line and move on, and that habit causes several small problems that add up.
Goods and services behave differently
Selling a part is retail. Doing the work is a service. They are treated as different kinds of transaction, and once a workshop reaches any size the difference shows up in what you file and what your documents should say.
There is also a simpler, immediate reason to separate them: business customers care. A fleet operator or a company paying for repairs needs to know what was parts and what was labour, both for their own records and because payments for services are commonly subject to a deduction at source, while payments for goods are treated differently.
A workshop that cannot break down its own invoice will be asked to, repeatedly, by exactly the customers worth having.
Parts are inventory, not just purchases
Workshops buy parts in two ways: ordered for a specific job, and stocked in advance because they move quickly.
Parts ordered for a job flow straight through. Stocked parts are inventory, which means money sitting on a shelf. Treating every bulk purchase as an immediate expense makes a profitable month look terrible and a slow month look fine.
Two habits help. Count the stock occasionally, so you know how much of your money is sitting in boxes. And watch the parts that have been on the shelf for two years, because those are not stock, they are a loss waiting to be recognised.
The margin question
Workshops make money two ways: a margin on parts and a rate for labour. Owners often have a clear idea of their labour rate and a very fuzzy idea of their parts margin.
Separating the two in your records tells you which side is actually carrying the shop. Many workshops discover their labour is underpriced and their parts margin is quietly covering it, which is fine until a customer starts supplying their own parts.
That last scenario is worth planning for. A customer bringing their own part turns the job into pure service, and if your labour rate assumed a parts margin, that job loses money.
Other things workshops get caught by
Customer property. A car in your bay is not your asset, and neither is a part a customer supplied. Keep them out of your inventory records.
Warranty work. A repair redone at no charge still consumes parts and hours. Recording it as nothing at all hides a real cost. Recording it properly tells you what your warranty is costing.
Cash jobs. Small repairs paid in cash with no document are the most common gap in the trade, and they are exactly the transactions that make a workshop's declared income look inconsistent with its parts purchases.
Tools and equipment. A lift or a diagnostic machine is a long-lived asset, recognised across the years it serves you.
Practical footing
Break every invoice into parts and labour, even when the customer only reads the total.
Count your stock, and write off what will never sell.
Issue documents for cash jobs too.
Track warranty work as work.
Running a workshop and unsure how to treat parts and labour in your records? Ask AskOnward for a plain answer from the official BIR rules, so your invoices work for your business customers as well as your walk-ins.
This article is for general information and is not affiliated with the government. For official forms and the latest rules, see the Bureau of Internal Revenue at bir.gov.ph.