Tachograph rules and your hardware: what the law requires

Most UK operators thinking about the drivers' hours rules focus on one thing: time. How long a driver can spend at the wheel, when a break is due, how many hours of rest. Fair enough, that is where most penalties land. But tachograph rules go further than the time. They also set requirements for the device itself, the installation, the calibration, and the paperwork around it. And that is where some operators come unstuck. The data is in order, the analyses run, the driver debriefs are logged. And they still pick up a penalty at a DVSA encounter or desk-based assessment. Not for what is in the data, but for what is missing around it.

This guide walks through the hardware side of UK tachograph compliance: what the rules require of the device, the deadlines that have just passed or are coming up, and what DVSA looks at when it checks.

What do tachograph rules cover beyond drivers' hours?

UK tachograph rules sit on two assimilated regulations: assimilated Regulation (EC) 561/2006 (drivers' hours) and assimilated Regulation (EU) 165/2014 (the tachograph itself, the driver card, installation, and calibration). They were brought into UK law after Brexit, and "assimilated" is now the legal term gov.uk uses (it replaced "retained EU law" in 2024). The second of those, 165/2014, tends to drop out of the conversation because the drivers' hours rules do most of the heavy lifting in penalty headlines. It is also the one that gets you penalised at the device level.

In practice, assimilated Regulation (EU) 165/2014 covers four things:

1. Which type of tachograph your vehicle must have. Depending on the date of registration and use, that is an analogue tachograph, a digital tachograph, a smart 1 tachograph, or a smart 2 tachograph (full or transitional). Newly registered in-scope vehicles since 21 February 2024 must have a full or transitional smart 2 fitted. From 24 December 2025, newly registered goods vehicles must have a full smart 2.

1. Who can fit and calibrate the device. Only a vehicle manufacturer or an Approved Tachograph Centre (ATC) can install, calibrate, seal and repair a tachograph. A general garage does not qualify.

1. How often the tachograph must be calibrated. Digital and smart tachographs are recalibrated every two years (and after certain repairs or vehicle changes). Analogue tachographs are inspected every two years and recalibrated every six.

1. What documentation you must keep. The installation plaque on or near the tachograph, the calibration certificate from the ATC, and your download records. For DVSA, these are the evidence that the device reads accurately and is operated within the rules.

This is the hardware side of the rules. Not drivers' hours, not infringement analysis. Not the data. Only the device and what surrounds it.

What do the rules say about installation and sealing?

Installing a tachograph is not a job you hand to whoever is free. Assimilated Regulation (EU) 165/2014 sets three hard requirements.

Approved centres only. Installation, calibration and sealing must be done by a vehicle manufacturer or an Approved Tachograph Centre (ATC). DVSA holds a public register at gov.uk/find-approved-tachograph-centre-atc. An installation by an unapproved fitter has no legal standing, even if the device technically works.

Sealing. After installation or calibration, the device is sealed by the ATC. The seal shows that nothing has been touched inside the tachograph since the last calibration. If the seal is broken and not refitted at an ATC, DVSA treats it as a manipulation indicator. There is a narrow defence under GB legislation if you can show that breaking the seal was unavoidable, that immediate repair was not practicable, and that all other rules were being complied with. Otherwise, expect to be picked up on it.

Installation plaque. When the tachograph is fitted, an installation plaque is attached to or near the device, showing the inspection and calibration dates and the centre that issued them. Inspectors update the plaque at every recalibration. At a roadside encounter, the traffic examiner checks the plaque first.

The reasoning is simple. A tachograph is only trustworthy if there is a clear chain of who worked on it and when. Without that chain, the data carries no legal weight.

When does your tachograph need to be calibrated again?

For digital and smart tachographs, the rule is two years. Every two years the device must go to an ATC for a full recalibration. The technician checks whether the tachograph still records accurately, whether the seal is intact, and whether the software is up to date. The device then gets a new seal and the calibration certificate is reissued.

Calibration is also triggered by certain events. The rules require recalibration after:

• Any repair to the tachograph.
• A change to the vehicle registration.
• UTC time being out by more than 20 minutes.
• A change to the tyre circumference or characteristic coefficient (which happens when you fit different tyres or alter the drive train).

Analogue tachographs have a slightly different cycle: inspection every two years, full recalibration every six. They are increasingly rare on in-scope vehicles, but the rule still applies where they remain in use.

Miss one of these recalibration triggers and the tachograph drifts. The data does not match reality, and any drivers' hours analysis built on that data is suspect. This is exactly the kind of fault a DVSA encounter or desk-based assessment uncovers: tidy records, on a device that no longer reads true.

What is changing for hardware in 2025 and 2026?

DVSA is pouring resources into data-driven enforcement, and the hardware side of compliance is where some of the most active changes sit. Three things matter for your fleet.

Smart 2 deadlines. The UK timeline runs in stages.

• Newly registered in-scope vehicles since 21 February 2024 must have a smart 2 tachograph, full or transitional.
• From 24 December 2025, all newly registered goods vehicles must have a full smart 2.
• From 1 July 2026, a full smart 2 must be fitted into goods vehicles over 2.5 tonnes used on international journeys for hire and reward. Own-account international journeys (where driving is not the main activity) are exempt. Goods vehicles between 2.5 and 3.5 tonnes used only within the UK do not need a tachograph at all.

For existing vehicles operating only within the UK, an older tachograph (analogue, digital, or smart 1) can still be used. A faulty smart 1, though, must be replaced with a smart 2 in any case.

The difference between full and transitional smart 2 is location verification: the full smart 2 supports the Galileo (OSNMA) satellite authentication that blocks GPS spoofing, the transitional version does not. From 24 December 2025, full smart 2 is mandatory for newly registered vehicles.

Remote enforcement at the roadside. The DVSA Annual Report 2024-25 puts it directly: "We continued to work with manufacturers to increase the use of remote sensing equipment to read Second Generation Smart Tachograph data remotely, allowing non-intrusive checking as a targeting tool." A traffic examiner can flag a vehicle from the data without stopping it.

Counter-Fraud and Investigations. DVSA's Counter-Fraud and Investigations Directorate, working alongside Traffic Commissioners, treats tachograph manipulation as one of the most serious infringement categories. Cases reaching Public Inquiry can result in licence revocation and disqualification of the Transport Manager.

If your hardware records are in order, none of this changes much for you. If they are not, 2026 is when the exposure shows up.

What does DVSA check on your hardware?

A roadside encounter does not lead with your data. It often starts at the device. Four checks tend to come up first.

Is the device working? The first question is whether the tachograph is on, recording, and present at all in a vehicle that needs one. A broken or missing tachograph in an in-scope vehicle is an immediate infringement, even if the driver could not have done anything about it.

Is the seal intact? The examiner looks at the seal on the device. A broken seal that has not been refitted at an ATC counts as a manipulation indicator. A broken seal you can show was refitted at an ATC after a legitimate change is fine. Documentation, in other words, is what makes the difference.

What does the installation plaque say? The plaque on or near the tachograph shows the date of the last calibration. If that date is over two years old for a digital or smart device, the vehicle is running on an out-of-date calibration. That is an infringement on its own.

Which type of tachograph is fitted? For newly registered vehicles after 21 February 2024 without a full or transitional smart 2, or for vehicles on international hire-and-reward work without the correct smart 2, this is now enforcement territory. The examiner can decide on the spot whether the right type is fitted for the work the vehicle does.

Only after the hardware checks come the driver card, the data, and the drivers' hours analysis. An operator who has only prepared for the last step has missed the first four.

What can you do this week?

Three things you can put in motion without spending money.

One: make a hardware overview by vehicle. For each vehicle, list the type of tachograph fitted (analogue, digital, smart 1, full or transitional smart 2), the last calibration date, and the next one scheduled. A spreadsheet does the job. It shows you immediately where your hardware trail is exposed.

Two: check the workshop schedule. For any vehicle that needs a smart 2 retrofit, or that has a recalibration date approaching, ring an Approved Tachograph Centre for a planning slot. Waiting times rise as more operators reach the same deadlines.

Three: pull the calibration certificates from your records. Check what you have for each vehicle and which dates are approaching. At a desk-based assessment, you need to be able to produce the records that show your hardware compliance. The legal duty under assimilated rules is to be able to produce records to enforcement officers for 12 months.

Key takeaways

• UK tachograph rules sit on two assimilated regulations: (EC) 561/2006 (drivers' hours) and (EU) 165/2014 (the device and the hardware), with working time covered by the Road Transport (Working Time) Regulations 2005
• Alongside data rules, assimilated Regulation (EU) 165/2014 sets requirements for the type of tachograph, installation by an Approved Tachograph Centre, sealing, and two-year recalibration for digital and smart devices
• Newly registered in-scope vehicles since 21 February 2024 must have a full or transitional smart 2; from 24 December 2025, newly registered goods vehicles must have a full smart 2; from 1 July 2026, full smart 2 must be fitted on goods vehicles over 2.5 tonnes on international hire-and-reward journeys
• A DVSA encounter typically starts at the device (is it working, is the seal intact, is the calibration current, is the right type fitted) before reaching the driver card and the data
• DVSA Counter-Fraud and Investigations is treating tachograph manipulation as a serious infringement category, with revocation and Transport Manager disqualification on the table at Public Inquiry
• The legal duty is to be able to produce records to enforcement officers for 12 months; in practice, keep calibration certificates and installation plaques across the life of the vehicle