How mechanics should invoice: a practical guide

On collection, with the old parts available to show. Nothing closes a repair conversation faster than handing someone the failed component while they read the invoice. Itemise labour and materials separately, put a real due date on it rather than "on receipt", and send it as a PDF the client can forward to whoever actually pays. For mechanics, the detail that matters most: parts and labour on separate lines, always — customers dispute a single lump sum far more often.

How to price the work

Labour at an hourly rate against published book times, parts at cost plus markup. This is one of the few trades where customers broadly accept and understand the structure.

What the lines should look like

For a service and MOT, a line that reads well is:

Full service, parts and labour itemised below

Specific enough that the person approving payment — often not the person who hired you — can see what they are paying for. Here is the same job as a finished invoice line:

Full service — parts and labour itemised
Oil and filter, air filter, pollen filter, plugs; 1.5 hours labour at £68/hr — £216.50

Deposits

None for routine servicing. Parts ordered for an older or unusual vehicle are usually paid up front.

Materials and markup

Parts and labour on separate lines, always. A single lump sum on a car repair is disputed far more often than the identical total split into two lines — because the customer cannot tell whether they are being charged for the part twice.

The mistake mechanics make most

Parts and labour on separate lines, always — customers dispute a single lump sum far more often.

Authorisation for extra work. You have the car on the ramp, you find a second fault, and fixing it while you are in there is obviously sensible. Do not. Ring first, get a yes, note the time of the call. Unauthorised work is the one thing a customer will refuse to pay for on principle.

Authorisation is the whole job

The car is on the ramp, you find a second fault, and fixing it now is obviously sensible. Do not. Ring, describe it, give a figure, note the time of the call, and only then continue. Unauthorised work is the one line a customer will refuse to pay on principle, and they are usually within their rights. A two-minute call protects the entire invoice, not just the extra.

Getting paid, in this trade specifically

Retail customers pay on collection, which is why you hold the car. Trade and fleet accounts are the exposure: they run on monthly statements and will happily accumulate six jobs before anyone looks at the total. Set a credit limit per account and mean it.

The rest is the same for everyone: what has to be on the document, how to number it, how to chase it and how long to keep it. If you are registered for tax, the rate and the label depend on your country.

EstimateBill tracks what is unpaid, reminds you on the due date, and writes the follow-up message for you in three tones. See how the reminders work.