Tachograph Calibration: How Often, Who Does It, and What to Check

Tachograph calibration is one of the compliance tasks most likely to slip through the cracks. Unlike a driver card download — which DVSA expects "at least every 28 calendar days" — recalibration of a digital or smart tachograph comes round only every 2 years per vehicle. That long interval is exactly what makes it easy to miss: the next due date feels remote until it is suddenly overdue.

The short answer. DVSA's guidance on the responsibilities of vehicle operators sets the intervals in two lines: "Analogue tachographs must be inspected every 2 years and recalibrated every 6 years", and digital and smart tachographs "must be recalibrated: every 2 years" — plus after any repair and a handful of other triggers listed below. The work must be done "either by a vehicle manufacturer or an approved tachograph calibration centre", and you can find one with GOV.UK's Approved Tachograph Centre finder.

This guide covers when calibration is due, who can do it, what the check covers, how to track it, and what to do if it has lapsed.

General guidance, not legal advice. Tachograph calibration and inspection requirements come from assimilated Regulation (EU) 165/2014 and DVSA's drivers' hours guidance for Great Britain. Northern Ireland keeps its own list of approved centres. Always check current DVSA guidance for your vehicle and tachograph type.

Why Calibration Is a Legal Requirement

DVSA lists it among the operator's own duties: operators must "ensure that tachographs have been calibrated, inspected and re-calibrated in line with the rules." The same guidance states that "All tachographs used for recording drivers' hours, whether analogue, digital or smart, must be properly installed, calibrated and sealed."

The two-year floor for inspections comes from the regulation itself. Article 23 of Regulation (EU) No 165/2014, as it applies in the UK, says: "Tachographs shall be subject to regular inspection by approved workshops. Regular inspections shall be carried out at least every two years."

How Often Must an Analogue Tachograph Be Checked?

This is the question most people arrive with, and the answer is two different clocks:

• Inspection: every 2 years at an approved calibration centre.
• Recalibration: every 6 years.

DVSA's wording is exactly that: "Analogue tachographs must be inspected every 2 years and recalibrated every 6 years." So an analogue unit visits a centre every two years, and every third visit is usually the recalibration rather than an inspection.

When Digital and Smart Tachographs Must Be Recalibrated

For digital and smart tachographs, DVSA lists the triggers. They "must be recalibrated":

• "every 2 years"
• "after any repair"
• "if the vehicle registration number changes"
• "if UTC is out by more than 20 minutes"
• "after an alteration to the circumference of the tyres or characteristic coefficient"

The tyre trigger catches people out: fitting a different tyre size changes the distance the tachograph thinks the vehicle has travelled, so it needs recalibrating even though nothing has gone wrong.

Before any vehicle goes into service — new or used — the same rule applies: "Operators must ensure that these tachograph requirements are complied with before a new or used vehicle goes into service." A used vehicle bought with a calibration close to expiry is your problem from the day you put it on the licence.

Which type you have depends on when the vehicle was first registered. GOV.UK's tachographs guidance says vehicles registered between 15 June 2019 and 20 February 2024 "must use either a smart 1 or a full or transitional smart 2 tachograph", and from 24 December 2025 "You must use a full smart 2 tachograph". Smart units sit on the same 2-year recalibration clock as digital ones.

Who Can Calibrate a Tachograph

Calibration must be performed "either by a vehicle manufacturer or an approved tachograph calibration centre." You cannot do it yourself, and a general HGV workshop without approval cannot do it either.

To find a centre near you, use GOV.UK's Approved Tachograph Centre finder, which lets you "find an Approved Tachograph Centre (ATC) to have a tachograph installed, calibrated or inspected." It adds a practical warning: "You will have to find the right centre for the type of tachograph you have - digital or analogue." Not every centre handles both — check before booking an analogue unit.

In Northern Ireland, nidirect publishes a separate list of approved tachograph centres, showing which handle analogue and which digital units.

What the Inspection Covers

Article 23 sets the minimum content of a periodic inspection. It "shall check at least the following":

• "the tachograph is correctly fitted and appropriate for the vehicle"
• "the tachograph is working properly"
• "the tachograph carries the type-approval mark"
• "the installation plaque is affixed"
• "all seals are intact and effective"
• "there are no manipulation devices attached to the tachograph or traces of the use of such devices"
• "the tyre size and the actual circumference of the tyres"

Afterwards, DVSA notes that "Tachograph calibration centres will issue a certificate showing details of any inspection conducted." Keep that certificate in the vehicle's file — not just the plaque on the vehicle.

The Plaque: Your First Check

DVSA requires that "An installation plaque must be fixed to or near the tachograph", and that "Inspection and recalibration dates are shown on the plaque and updated by calibration centres."

That makes the plaque the quickest way to check a vehicle's status yourself. Read the date of the last calibration or inspection, add the interval (2 years for digital and smart; for analogue, 2 years to the next inspection and 6 years from the last recalibration), and put the result in your planner.

Seals are a separate visual check: the inspection confirms "all seals are intact and effective", so a broken seal you spot between visits is worth raising with your centre straight away. GB legislation provides a narrow defence where "a seal is broken and the breaking of the seal was unavoidable and it could not be immediately repaired", provided the other rules are being complied with — it is not a reason to leave it.

Tracking Calibration Deadlines

For a fleet of 2–3 vehicles, calibration dates are easy to lose because they are vehicle-specific and staggered — each vehicle has its own clock running from its last calibration.

The licensing guide expects them on the same plan as your inspections: a maintenance planner "setting preventative maintenance inspection dates at least 6 months in advance and including the MOT and other testing or calibration dates". In practice, add each vehicle's next calibration date to your planner with a reminder well ahead, so a centre visit can be booked around work rather than squeezed in at the last minute. See our vehicle maintenance planner guide for structuring it, or our fleet compliance software guide if you are choosing a system that tracks expiry dates.

What If Calibration Has Lapsed

If you find a vehicle with an overdue calibration:

1. Stop using it for work that needs the tachograph until it is calibrated — the requirement is to have it calibrated "in line with the rules", and an overdue date on the plaque is visible to anyone who looks.
2. Book it in at an approved centre that handles that type of unit.
3. Download the vehicle unit and driver cards as normal before and after — your download duties carry on regardless.
4. Record what happened — when you found the lapse, what you did, and when calibration was completed.
5. Fix the tracking gap that let it happen. One lapse looks like an oversight; a pattern looks like a system that is not working, which is what a traffic commissioner assesses.

Roadside encounters feed your Operator Compliance Risk Score, which DVSA uses "to calculate the risk of an operator not following the rules on roadworthiness (the condition of its vehicles) and traffic, for example drivers' hours or weighing checks" (GOV.UK OCRS guidance).

Cost

There is no single published price for tachograph calibration in Great Britain. Some centres publish their own fee — Sefton Council's testing station in Bootle, for example, lists "Tachograph Calibration - £130 + VAT" (Sefton Council, page last updated 1 April 2026) — but that is one centre's price, so the practical route is to ask two or three centres from the GOV.UK finder for a quote — and to ask whether the price differs for analogue, digital and smart units, and whether it includes any recalibration triggered by work found during the visit.

Whatever the figure, budget for it per vehicle on a 2-year cycle (or the analogue inspection/recalibration cycle), alongside MOT and inspection costs.

Calibration vs Inspection vs Repair

• Recalibration — digital and smart: every 2 years and after the listed triggers; analogue: every 6 years.
• Inspection — analogue: every 2 years between recalibrations. Article 23 sets the two-year inspection floor for all tachographs.
• Repair — event-driven. For digital and smart units, DVSA requires recalibration "after any repair". If a tachograph breaks down, the assimilated rules require that "it must be repaired as soon as possible", and "If the vehicle is unable to return to its base within a week the repair must be carried out en route."

Tachograph Calibration and Your O-Licence

The O-licence compliance checklist covers calibration as a named item alongside safety inspections, MOT expiry and driver records. The plaque, the centre's certificate and your planner entry together form the audit trail — keep all three, and file the certificate with each vehicle's maintenance records.

Sources

• Drivers' hours, goods vehicles: responsibilities of vehicle operators (tachograph calibration and inspection) — GOV.UK
• Regulation (EU) No 165/2014, Article 23 (inspections of tachographs) — legislation.gov.uk
• Find your local Approved Tachograph Centre (ATC) — GOV.UK
• Approved tachograph centres (Northern Ireland) — nidirect
• Tachographs — GOV.UK
• Operator Compliance Risk Score — GOV.UK