BayApproveSetting a diagnostic fee policy as a mobile mechanic
Updated October 22, 2026 · For mobile and independent mechanics
Diagnosis is skilled work. Tracking down an intermittent electrical fault can take longer than the repair itself. Yet many mechanics give it away, hoping to win the repair, and then lose the job to someone cheaper after doing the hard part.
A clear diagnostic fee policy, explained before you start, gets you paid for that work and filters out customers who only want a free opinion.
Flat fee or hourly
A flat diagnostic fee is easy to explain and covers most straightforward checks: a scan, a test drive, a visual inspection. Hourly diagnosis suits harder problems, with an agreed first block of time and approval before going further. Many mechanics use a flat fee for the first look and hourly beyond it.
Credit it toward the repair, or not
Some mechanics credit the diagnostic fee against the repair if the customer goes ahead; others keep it separate. Crediting it encourages customers to book the repair with you. Keeping it separate is simpler when the diagnosis took real time. Pick one, and say which when you quote.
Explain it before you start
- When the customer books, state the diagnostic fee and what it covers.
- Get their OK in writing before you start.
- After diagnosis, send the findings and the repair estimate for separate approval.
- Collect the diagnostic fee whether or not they approve the repair.
Mobile call-out fees
Mobile mechanics also cover travel. Some include travel in the diagnostic fee within a service area and add a charge beyond it. Whatever you choose, quote it up front.
Common questions
- Won’t a diagnostic fee scare customers off?
- It can put off customers who only want a free opinion. Customers who need the car fixed generally accept a fair fee, especially if it’s credited toward the repair.