Glossary
The vocabulary of service records, defined plainly. Each entry has its own anchor, so you can link straight to a definition from anywhere.
- Approved used
A manufacturer-backed used-car scheme with an inspection and warranty. Approved-used cars usually come with a documented service history and a multi-point check that sits alongside it.
See also: Main dealer, Full Service History
- Cambelt (timing belt)
A rubber belt driving the engine's valve gear, replaced at a set interval in years and miles. Some engines use a chain instead, which normally has no scheduled replacement; a growing number use a wet belt that runs in engine oil, where the interval is tied closely to oil condition. Because a snapped belt usually destroys the engine, a documented cambelt change is one of the most valuable entries in a service history — and intervals differ between engines within the same brand, so the figure has to be checked per engine rather than per badge.
See also: Service interval, Full Service History, Wet belt (belt-in-oil), Timing chain, Interference engine
Go deeper: Cambelt intervals by engine
- Condition Based ServicingCBS
BMW and MINI's system that monitors components and flags service needs based on actual condition and use. Owner apps typically show CBS status — what is due next — rather than a stamped list of completed work.
See also: Variable (Longlife) servicing, Service interval
- Dealer Management SystemDMS
The software a dealer network uses to run its business, including the service records. When a manufacturer 'holds' your history, it usually lives in the DMS and is retrieved by VIN.
See also: Digital Service Record, Vehicle Identification Number
- Diesel Particulate FilterDPF
A filter in the exhaust that traps soot and periodically burns it off in a process called regeneration. Two consequences show up in service records. It dictates the oil: ash from a non-low-SAPS oil accumulates in the filter instead of burning off, so filter-equipped engines carry a low-SAPS approval that is not optional. And regeneration injects extra fuel, some of which reaches the sump and dilutes the oil — which is why short-journey use, where regenerations start but never complete, is harder on an engine than the mileage suggests. Ford cut the published belt interval on the 2.0 EcoBlue and attributed it to exactly this, and oil dilution is among the cited causes of chain wear on the JLR Ingenium.
See also: Low-SAPS oil, Oil approval (manufacturer specification), Wet belt (belt-in-oil), Service interval
Go deeper: Oil approvals by engine
- Digital Service BookletDSB
A manufacturer-specific name for a digital service record, used notably by Mercedes-Benz. It replaced the stamped paper booklet with an electronic equivalent tied to the VIN.
See also: Digital Service Record
- Digital Service RecordDSR
A car's maintenance history held electronically in the manufacturer or dealer system rather than a paper book. Entries are keyed to the vehicle's VIN and created by authenticated dealer logins, which makes them hard to lose or forge.
See also: Digital Service Booklet, Vehicle Identification Number, Full Service History
- Digital Service ScheduleDSS
The Volkswagen Group's term for its shared digital service record, used across the volume brands — VW, Audi, SEAT, Škoda and CUPRA. Because it spans those brands, a single car's history can include entries created at different brands' dealers. Porsche and Bentley run their own record systems under the same group.
See also: Digital Service Record
- DSG / dual-clutch transmissionDirekt-Schalt-Getriebe
Volkswagen Group's name for its dual-clutch automatic; Audi sells the same units as S tronic. The distinction that matters for servicing is wet versus dry: in a wet unit the clutches run in the gear oil, which picks up friction material and normally has a scheduled change, while a dry unit's clutches sit outside the oil and the fill is usually rated for life. The badge on the car does not tell you which you have.
See also: Lifetime fill (“filled for life”), Service interval
Go deeper: Transmission intervals by unit
- Electronic Parking BrakeEPB
An electric handbrake that needs a diagnostic tool to wind back for brake servicing. It is one reason some jobs must be done by a garage with the right equipment, franchised or independent.
See also: Repair and Maintenance Information
- Franchised dealer
A dealer authorised by a manufacturer to sell and service its cars. Franchised dealers create and can retrieve entries in the manufacturer's digital service record; independents generally cannot.
See also: Independent garage, Main dealer
- Full Service HistoryFSH
A complete, unbroken record of a car's scheduled servicing, whether digital, paper or both. 'Full' generally means every manufacturer-recommended service is documented; gaps downgrade it to part service history.
See also: Part Service History, Service stamp
- Grey import / parallel import
A car brought into the UK outside the manufacturer's official import channel. Its early history often sits in an overseas system that never synced to the UK, creating apparent gaps.
See also: Vehicle Identification Number
- Independent garage
A garage not tied to a manufacturer. Independent servicing is legitimate and does not by itself invalidate a manufacturer's warranty, provided the correct schedule and matching-quality parts are used (see block exemption). The work may not appear in the manufacturer's digital record unless the garage uses a compatible system.
See also: Franchised dealer, Motor Vehicle Block Exemption
- Interference engine
An engine where the valves and pistons occupy the same space at different moments, so a timing failure lets them collide. Most modern engines are interference designs. It is the reason a cambelt failure usually means a replacement engine rather than a replacement belt, and the reason the interval is worth taking seriously rather than stretching.
See also: Cambelt (timing belt), Wet belt (belt-in-oil), Timing chain
- Lifetime fill (“filled for life”)
A manufacturer position that a gearbox or differential fluid has no scheduled replacement. It describes the maintenance schedule, not a guarantee about the component — and it is why many service histories show no gearbox entry at all, which is not the same as one being skipped. Independent specialists frequently change fluids the manufacturer rates as lifetime, particularly where a mechatronic unit shares the same fill.
See also: DSG / dual-clutch transmission, Service interval
- Low-SAPS oil
Oil formulated with reduced Sulphated Ash, Phosphorus and Sulphur. The ash is the point: in an engine with a diesel or petrol particulate filter, ash from ordinary oil accumulates in the filter rather than burning off during regeneration, and the filter progressively blocks. Low-SAPS approvals — VW 507 00, BMW Longlife-04, PSA B71 2312, Fiat 9.55535-DS1 among them — exist to prevent that. Using a non-low-SAPS oil in a filter-equipped engine does not announce itself; it shortens the filter's life quietly, and the bill arrives years later.
See also: Oil approval (manufacturer specification), Diesel Particulate Filter
Go deeper: Which engines specify a low-SAPS approval
- Main dealer
Everyday term for a franchised dealer. 'Main-dealer history' means servicing done within the manufacturer's authorised network, which usually carries the most weight at resale.
See also: Franchised dealer, Approved used
- MOT
The annual roadworthiness test. In Great Britain most cars need their first MOT at three years old; in Northern Ireland it is four years, and tests are carried out at DVA centres rather than private garages. The MOT history — mileage readings, advisories and failures — is public on GOV.UK and is a useful independent cross-check against a service record, though a car younger than its first test has none.
See also: Service interval
- Motor Vehicle Block Exemption
The competition rule that means having a car serviced by an independent garage does not by itself void the manufacturer's warranty, provided the work follows the correct schedule and uses matching-quality parts. In the UK it is now the Motor Vehicle Block Exemption Order 2023, which replaced the retained EU regulation on 1 June 2023 and runs to 31 May 2029. Strictly it is competition law about agreements between manufacturers and their networks, but its practical effect is your right to choose where the car is maintained.
See also: Independent garage, Repair and Maintenance Information, OEM
- OEMOriginal Equipment Manufacturer
The company that made the vehicle or a genuine part. Under block exemption a manufacturer cannot insist on its own branded parts, but the parts used must be of matching quality and the schedule must be followed — otherwise a warranty claim connected to that work can be refused.
See also: Motor Vehicle Block Exemption, Independent garage
- Oil approval (manufacturer specification)
A manufacturer's own standard for engine oil — VW 504 00, Ford WSS-M2C950-A, BMW Longlife-04, PSA B71 2312, MB-Approval 229.51. It is not the same thing as the viscosity, and it is the part that matters. Viscosity (5W-30, 0W-20) describes how the oil flows; the approval describes what it is made of and what it was tested against, and two oils can share a viscosity while meeting completely different approvals. That is how the wrong oil gets bought — the number on the front of the bottle matches and the specification on the back does not. Which approval applies is often decided by something other than the engine: on BMW petrols and Porsche flat-sixes it follows whether a particulate filter is fitted, and on VW Group cars it follows whether the car is on a fixed or Longlife service regime.
See also: Low-SAPS oil, Service interval, Variable (Longlife) servicing, Wet belt (belt-in-oil)
Go deeper: Oil approvals by engine
- Part Service HistoryPSH
A record with some services documented but not all. Common causes are switching between dealers and independents, lost paperwork, or a period the current owner can't account for.
See also: Full Service History
- Registered keeper
The person responsible for a vehicle on the DVLA record — not necessarily the legal owner. Owner portals and dealer record requests are usually tied to the keeper or a verified owner account.
See also: V5C (logbook)
- Repair and Maintenance InformationRMI
The technical data a garage needs to repair and service a vehicle — procedures, torque figures, diagrams, software. Under vehicle type-approval rules manufacturers are required to make RMI available to independents on a non-discriminatory basis, usually for a fee. That obligation covers generic repair information, not reading an individual car's franchised service history.
See also: SERMI, Motor Vehicle Block Exemption, Independent garage
- SERMISecurity-Related Repair and Maintenance Information scheme
An accreditation scheme that lets approved independent operators access security-related information — anti-theft, immobiliser and key data — through manufacturer portals. It began in the EU and went live in the UK on 1 April 2026, administered by RMI Standards and Certification; UK participation is voluntary where the EU mandates it. It concerns security data, not your car's service history, and is often misunderstood on that point.
See also: Repair and Maintenance Information, Independent garage
- Service interval
How often a car should be serviced, set by time and/or mileage. Intervals vary by brand and can be fixed or variable, which affects how a legitimate record should look.
See also: Variable (Longlife) servicing, Condition Based Servicing
- Service stamp
The dealer or garage stamp, date and mileage entered in a paper service book at each service. Generic stamps can be bought cheaply, which is one reason digital records have become more trusted.
See also: Digital Service Record
- Service, Maintenance and RepairSMR
A fleet and trade term for the ongoing upkeep of a vehicle. Fleet-managed cars often have SMR records held by a leasing or management company rather than in the manufacturer's owner-facing system.
See also: Service interval
- Timing chain
A metal chain driving the valve gear in place of a belt. There is normally no scheduled replacement, which is why a chain-engine service history will never show one — an absence that is correct rather than a gap. It is still a wear item on some engines: chain stretch is diagnosed by measuring camshaft timing deviation rather than pre-empted at a mileage, so a complete record tells you nothing about its condition.
See also: Cambelt (timing belt), Wet belt (belt-in-oil), Service interval
Go deeper: Belt or chain, by engine
- V5C (logbook)
The DVLA registration certificate showing the registered keeper and the vehicle's details, including the VIN. Dealers often ask to see it as proof of ownership before releasing records.
See also: Vehicle Identification Number, Registered keeper
- Variable (Longlife) servicing
A regime where the car calculates when a service is due from how it is driven, rather than at a fixed interval. Volkswagen Group's Longlife is the best-known example; it can make service spacing look irregular when it is correct.
See also: Service interval, Condition Based Servicing
- Vehicle Identification NumberVIN
The unique 17-character identifier stamped on a car and printed on the V5C. Digital service records are keyed to the VIN, so it is the anchor for retrieving a car's history.
See also: Vehicle Registration Mark, V5C (logbook)
- Vehicle Registration MarkVRM
The number plate. It can change over a car's life (private plates, cherished transfers), so records are ultimately tied to the VIN rather than the VRM.
See also: Vehicle Identification Number
- Wet belt (belt-in-oil)
A cambelt that runs inside the engine, submerged in oil, rather than outside behind a cover. It cuts friction and helps meet emissions targets, but the belt degrades in the oil and the debris it sheds can block the oil pickup — so the engine typically fails from oil starvation rather than from a broken belt. Ford and Stellantis have both shortened their published intervals, retrospectively, which means a car's handbook can state a figure its maker no longer stands behind.
See also: Cambelt (timing belt), Service interval, Interference engine
Go deeper: Which engines have a wet belt