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Analogue, digital and smart tachographs explained for UK operators: card types, what each records, calibration, and the smart 2 retrofit deadlines.
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A tachograph is the recording device fitted to most heavy goods vehicles and larger passenger vehicles that automatically logs how the vehicle is driven and how the driver spends their working day - driving, other work, availability and rest. It exists to enforce the drivers’ hours and working time rules that protect road safety and support fair competition, and it produces the single most important set of evidence DVSA examines, both at the roadside and at your operating centre.
In Great Britain the rules now sit in assimilated law; the body of former EU regulation kept in force after Brexit (and previously referred to simply as “EU rules”). The two instruments that matter here are Regulation (EC) No 561/2006 on drivers’ hours and Regulation (EU) No 165/2014 on tachographs, as they have effect in UK law. Journeys to, from or through certain non-EU countries can instead fall under the AETR agreement.
In broad terms, a tachograph is required for:
A range of vehicles and operations are exempt, for example certain short-radius, specialised or low-speed work. Don’t assume an exemption applies without checking it.
Which type you have depends almost entirely on when the vehicle was first registered. One of the most common misconceptions is that every tachograph today is “smart”. That isn’t the case. There are three families of devices, and older types remain perfectly legal in the vehicles they were fitted to, provided those vehicles aren’t used internationally.
The original technology: three styluses cut traces into a wax-coated paper chart to record speed, distance and the driver’s activity. The driver completes the centrefield of the chart by hand. Analogue units are found in in-scope vehicles first registered before 1 May 2006 and are still permitted in those vehicles for domestic work.
From 1 May 2006, newly registered in-scope vehicles had to be fitted with a digital tachograph. Instead of a paper chart, data is stored electronically, partly in the vehicle and partly on each driver’s smart card. First-generation digital units have no satellite positioning.
From June 2019, newly registered in-scope vehicles had to be fitted with a smart tachograph. A smart tachograph is a digital tachograph with two extra capabilities: satellite positioning (GNSS), and a short-range radio link (DSRC) that lets an enforcement officer read selected data remotely as the vehicle passes a checkpoint. That remote reading can’t by itself trigger a fine. It only flags a vehicle; the officer may then choose to stop and check.
There are two generations of smart tachograph, and the difference matters for international work:
You may also see smart 2 units described as “transitional” or “full”. The only practical difference is that a transitional unit does not yet have the Galileo (OSNMA) position-verification feature active in its software; a full unit does.
The smart 2 retrofit deadlines apply only to vehicles used on international journeys between the UK and the EU. A vehicle that operates solely within the UK can keep the tachograph it was originally fitted with. But a single cross-border trip brings a vehicle into scope, so check honestly how your vehicles are actually used.
Two points trip people up. First, the 1 July 2026 change only catches vehicles over 2.5 tonnes used internationally for hire and reward; if the international trip is on your own account and driving isn’t the driver’s main activity, no tachograph is required. Second, if you’re unsure which deadline bites, work through it in order: is the vehicle in scope at all, does it ever cross a border, and what is fitted to it now? UK fitment dates are set out in the DVSA approved tachograph centre special notice 01-23.
One further change affects new vehicles. The transitional smart 2 unit (without active Galileo position verification) could only be fitted to newly registered vehicles up to 24 December 2025; from that date a newly registered vehicle must be fitted with a full smart 2, as confirmed in DVSA special notice 03-25. Transitional units already fitted before that date don’t need a further upgrade.
Don’t read the goods-vehicle table above as applying to international coach and bus work. Since 21 April 2025, under the Drivers’ Hours and Tachographs (Amendment and Modification) Regulations 2025, PSVs with more than 10 seats on international journeys between the UK and the EU operate under the AETR agreement rather than the assimilated rules. AETR requires a digital tachograph but does not carry the smart 2 retrofit timetable, and the roadside record requirement for PSVs stays at 28 days rather than the 56 days that applies to international goods work.
The digital and smart system runs on four types of smart card, each with a different job:
Personal to the driver, like a driving licence, and valid for five years. It must be inserted before driving - in slot 1 when driving, slot 2 when acting as co-driver on a double-manned trip. It holds roughly the last 28 days of that driver’s activity and travels with them from vehicle to vehicle. Driving an in-scope digital or smart vehicle without a valid driver card is one of the most serious tachograph offences.
Common misconception: the company card does not store your driving data. It is the key that authorises downloads from your vehicles and “locks” your data so competitors and other third parties can’t read it. The activity itself lives in the vehicle unit and on the driver cards - the company card simply unlocks and retrieves it.
A red card issued to a named, qualified technician working at an Approved Tachograph Centre, valid for one year. It is what allows a unit to be installed, activated, calibrated and checked. It is issued to the individual technician, not to the centre.
A blue card held by DVSA examiners and the police. It gives full access to the data held in the vehicle unit and on driver cards, and it overrides any company lock an operator has applied.
A digital or smart tachograph keeps its record in two places. The vehicle unit (VU) is the fixed device in the cab. It records everything done in that vehicle; every driver who used it, speed, distance, events and faults and holds roughly the last 365 days before the oldest data is overwritten. The driver card holds the individual driver’s own activity, roughly the last 28 days, and goes with the driver into whatever vehicle they next drive.
Think of them as two halves of one record: the vehicle’s view and the driver’s view, which should agree. How often each must be downloaded, and how long the data must be kept and analysed, is covered separately.
When the vehicle is moving, the tachograph records driving automatically. When it stops, the driver must use the mode switch to record what they’re actually doing. There are four activities:
When the vehicle stops, the unit defaults to a pre-set mode chosen at calibration, so the driver must actively select the correct activity rather than rely on the default. Selecting the wrong mode, or failing to switch at all, is an offence and produces gaps that look suspicious in analysis.
Manual entries are a legal requirement, not a nicety. The tachograph can only record automatically while the card is in the unit, so any activity away from the vehicle has to be entered by hand; typically the work or rest before the card goes in at the start of a shift, and time spent on rest or other duties away from the vehicle. Miss these and the record shows unexplained gaps, which DVSA may treat as undeclared driving.
Across the vehicle unit and the driver card, the system captures:
A smart tachograph adds satellite position data automatically: it records the vehicle’s position at the start of the daily working period, after every three hours of accumulated driving, and at the end of the working period. A smart 2 unit goes further, recording border crossings and loading/unloading positions automatically rather than relying on the driver to key them in.
All times are stored in UTC (effectively GMT), regardless of what the display shows, so be careful with manual entries, and remember the stored record runs an hour behind local clocks during British Summer Time. The specific drivers’ hours limits the record is checked against are covered separately.
Digital and smart tachographs must be recalibrated at least every two years. Analogue units must be inspected every two years and recalibrated every six. Recalibration is also needed after certain changes: a repair affecting the unit, a change of registration mark, a change in tyre size or rolling circumference, or the clock drifting too far from UTC.
Only an Approved Tachograph Centre (ATC), using a technician’s workshop card, may calibrate and seal a unit, and a calibration plaque inside the vehicle records the date. Driving on a lapsed calibration is an offence for both the driver and the operator, so it’s worth tracking calibration dates alongside MOT and inspection schedules.
There is a defined procedure, and following it precisely is what keeps a driver legal and an operator protected:
Important distinction: a forgotten card is not a lost card. If you’ve simply left your card at home, you must retrieve it before driving - the printout procedure above does not cover forgetting it, and driving without it in that situation is an offence.
If the tachograph itself stops working or develops a fault, it must be repaired by an Approved Tachograph Centre as soon as circumstances allow. If the vehicle can’t get back to base within a week, the repair must be carried out en route. While the vehicle is away from base, the driver keeps the record going with printouts and manual entries in the same way as for a lost card, so keep a spare roll of approved print paper in every vehicle.
When a digital or smart unit is repaired or replaced, ask the centre to download any data still held in it. If the data can’t be recovered, the centre should issue a certificate of undownloadability, which you must keep for at least 12 months. DVSA operator guidance sets out both points.
Most “technical” infringements come from a short list of recurring problems. Watch for:
Most technical problems are cheaper to catch in the yard than at the roadside. For each vehicle, it’s worth confirming:
Getting the right hardware fitted and calibrated is only half the job. The value is in what the data tells you: spotting infringements early, closing record gaps and being able to show DVSA a clean, complete picture.
Keeping on top of downloads and analysis, and identifying the infringements in the data, is precisely the burden Tacho Agent takes off operators, so your team can get on with running the fleet.
This article is provided for general guidance only and reflects our understanding of the rules as they apply in Great Britain as at the date shown on this page. It is not legal advice and should not be relied on as a substitute for advice tailored to your specific operation.
Drivers' hours, tachograph, working time and operator licensing rules are detailed and change over time, and some requirements differ in Northern Ireland and for international journeys. Always check the current guidance on GOV.UK and the underlying legislation on legislation.gov.uk, and consult your transport manager or a qualified compliance professional before acting.
To the fullest extent permitted by law, Tacho Agent Ltd accepts no liability for any loss arising from action taken, or not taken, in reliance on this article. Nothing here excludes or limits any liability that cannot lawfully be excluded, including for death or personal injury caused by negligence or for fraud. Use of this article is also governed by our Terms of Use.
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