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Maintenance and tyres , Buying a used car , Costs and money · Updated 2026-10-15

How to read a service book

A service book, together with invoices and workshop records, is the nearest thing a car has to a medical history. Reading it carefully tells you how the car was treated and what may be due soon. This guide shows what to look for.

Stamps versus invoices

A service book with regular stamps is a good sign, but stamps alone are easy to fake or fill in later. Invoices and work orders are stronger evidence because they list the actual work, parts and mileage. The best case is stamps that are backed by matching invoices from identifiable workshops.

Intervals

Manufacturers set service intervals by time and by distance, whichever comes first. Check the car's manual for the intervals and compare them with the entries. Cars used mostly for short trips or in harsh conditions often need more frequent service than the minimum.

• Are services spread evenly, or are there long irregular gaps?
• Were the entries made in a plausible order and on plausible dates?
• Is the handwriting, ink and stamp style consistent for work supposedly done by different workshops?

Gaps and mileage consistency

Mileage should rise steadily from entry to entry. Look for a sudden drop, a long period without any service, or an unexplained jump. Compare the last recorded mileage with the odometer and with other records, such as inspection reports. A seller should be able to explain any gap, for example a long period when the car was not driven.

Key items to look for

• Engine oil and filter: regular changes are the cheapest protection for the engine.
• Timing belt or chain: if the engine uses a belt, find out when it was last replaced. A failure can destroy the engine, so a missing or overdue entry is a serious point for negotiation.
• Brake fluid: it absorbs moisture and should be changed on a time schedule, not only by distance.
• Other fluids and filters: coolant, air, fuel and cabin filters, and gearbox oil where the maker specifies it.
• Brakes, tyres and battery: signs they were replaced when needed.

Questions to ask the seller

• Where was the car serviced, and can I contact the workshop?
• Who has owned the car, and for how long?
• Has anything major been repaired or replaced, and do you have the invoices?
• What is due next, and when was it last done?

If the history is missing

A car without any history is not necessarily bad, but it carries more risk. Ask for a clear explanation, lower your offer to cover the work you may need to do straight away, and have a mechanic inspect the car thoroughly. When you buy, start your own record from day one.

Documents Service history Used car