Car Service Intervals Explained: How Often to Service a Car

How Often Should You Service a Car?

As a general rule, a car needs a service every 12 months or every 10,000–12,000 miles, whichever comes first. Most manufacturers split that into a smaller “interim” service and a larger “full” service on alternating cycles, with bigger items grouped into a “major” service every few years. But the honest answer is that the right interval is the one in your car's handbook, because it varies by make, model, engine and whether the car uses a fixed or a variable schedule.

This guide explains what the intervals mean, why both time and mileage matter, what each service actually includes, and how to check whether a used car has genuinely been kept to its schedule — which is where a service history check comes in.

Time vs Mileage: “Whichever Comes First”

Service intervals are almost always written as two numbers — a time limit and a mileage limit — and you act on whichever you reach first.

• High-mileage drivers hit the mileage figure before the year is out. A rep covering 25,000 miles a year might need two services in twelve months.
• Low-mileage drivers hit the time limit first. Even a car that barely moves needs an annual service, because engine oil absorbs moisture and breaks down over time, seals and rubber age, and brake fluid attracts water whether you drive or not.

That's why “I've hardly used it” isn't a reason to skip a service. Time-based degradation happens on the driveway as surely as on the motorway.

Interim, Full and Major Services

Not all services are equal. The three tiers you'll see quoted by garages map roughly to how much gets checked and replaced:

Interim service (every ~6 months / 6,000 miles)

A lighter safety-and-health check, popular with high-mileage drivers who want an oil change between full services. Typically engine oil and filter, fluid top-ups, and a visual inspection of brakes, tyres, lights and steering.

Full service (every 12 months / 12,000 miles)

The annual standard. Everything in an interim service plus more filters (air, fuel or pollen as scheduled), a wider inspection checklist, and closer attention to wear items. This is the service most buyers mean when they talk about “full service history”.

Major service (every 2–4 years, per schedule)

Adds the bigger, longer-life items the manufacturer schedules less often — spark plugs, brake fluid change, cabin filter, and sometimes the cambelt and coolant. It costs more but heads off expensive failures. The cambelt in particular is critical: our cambelt and service history guide explains why a missed belt change can destroy an engine.

Fixed vs Variable (Condition-Based) Servicing

There are two philosophies for deciding when a service is due, and knowing which your car uses matters:

• Fixed servicing uses set intervals — e.g. every 12 months or 12,000 miles, full stop. Simple and predictable, and common on many mainstream models.
• Variable or condition-based servicing lets the car work out its own interval from how it's driven — mileage, driving style, engine hours, cold starts and oil condition. BMW's Condition Based Servicing and the variable systems on Mercedes, Vauxhall, Volkswagen Group and others all work this way, and the dashboard tells you when a service is due.

Variable servicing can stretch intervals for gentle, long-distance drivers — but short urban trips, lots of cold starts and hard driving pull them forward fast. Don't assume a flat 12,000 miles; trust the service indicator, and check the handbook for the maximum time limit that applies regardless of the reading. Manufacturers record all of this digitally, as our guide on how manufacturers record service history explains.

What Happens If You Skip Services

Missing the odd service by a few weeks won't wreck a car, but a habit of skipping them stacks up real costs:

• Accelerated wear. Old, degraded oil protects the engine less, and small problems that a service would catch early grow into big repair bills.
• Cambelt failure. The single most expensive thing to miss — a belt that snaps past its interval can destroy the engine outright.
• Warranty risk. A manufacturer or used-car warranty can be refused if you can't show the car was serviced on schedule. See service history and your car warranty for how gaps cost people claims.
• Lower resale value. A gap in the service history is one of the first things a buyer spots, and it drags the price down, as covered in what full service history means.

How to Check a Used Car Was Serviced on Schedule

Knowing the correct interval is only half the story when you're buying used — you also want proof the previous owners actually kept to it. The service history is the record of that: it shows the date and mileage of every service, so you can see at a glance whether the car was maintained on time or left to drift.

A service history check on FindServiceHistory retrieves the official manufacturer dealer record by registration, with the dates and mileages of each service, plus the full DVSA MOT history in the same report. It's £9.99, your card is only charged if records are found, and it turns “the seller says it's been serviced” into something you can actually verify. Brand-specific detail on intervals and records lives in our manufacturer guides, such as the BMW service history guide.

The Bottom Line

Service every 12 months or 10,000–12,000 miles as a baseline, follow your handbook and any dashboard service indicator for the exact interval, and don't let a low-mileage year tempt you into skipping. Keeping to schedule protects the engine, your warranty and your car's value — and when you're buying used, a full, on-time service record is the clearest sign the car in front of you has been genuinely looked after.

Buying? Check the record before you commit: enter the reg on FindServiceHistory to see the full service and MOT history in minutes.