Tachograph calibration and download intervals in Great Britain

Three intervals govern tachograph compliance in Great Britain: the unit itself must be inspected and recalibrated every 2 years, the vehicle unit downloaded at least every 90 days, and every driver card downloaded at least every 28 days. The downloaded data must be kept for at least 12 months — and where working time rules apply, those records for 2 years.

Calibration: the 2-year cycle

A digital or smart tachograph must be checked and recalibrated at an approved tachograph centre every 2 years. The centre verifies the unit records accurately for the specific vehicle and fits a calibration plaque showing the date — which is what a DVSA examiner looks for at the roadside. A recalibration is also required outside the cycle after certain events: a repair to the unit, a change of tyre size, or a change of vehicle registration. Analogue tachographs (now rare) follow a two-yearly inspection with a full recalibration every 6 years.

Newer vehicles carry the generation 2 smart tachograph, which adds automatic recording of border crossings and better tamper resistance. Vehicles over 3.5 tonnes used on international journeys had to be fitted with it by August 2025, and from 1 July 2026 vans between 2.5 and 3.5 tonnes on international work come into scope. For purely domestic GB work no retrofit is required, but the calibration cycle is the same whatever the generation.

Downloads: 90 days and 28 days

In GB the operator must download:

• the vehicle unit at least every 90 days;
• each driver card at least every 28 days.

These are legal maximums, not targets. Most operators download cards weekly or fortnightly: a card holds roughly 28 days of activity, so a card lost or damaged at the end of the window can take a month of records with it. Downloading is only half the duty — the data must also be analysed for infringements and the findings followed up with drivers.

Retention: 12 months, or 24 with working time

Downloaded tachograph data must be kept, unaltered and retrievable, for at least 12 months. Where the Road Transport (Working Time) Regulations 2005 apply to your drivers, working time records must be kept for 2 years after the period they cover — which is why many operators standardise on 24 months for everything.

What non-compliance costs

DVSA enforces with graduated fixed penalties — typically £100 to £300 per offence depending on seriousness — and since 2018 examiners can fine a driver at the roadside for up to 5 drivers' hours offences from the previous 28 days, so a single stop can add up to thousands of pounds. Serious or deliberate offences (tampering above all) are prosecuted, with unlimited fines possible. And every infringement feeds your OCRS, inviting more stops and ultimately a public inquiry — see what the Traffic Commissioner can do about your O-licence.

Four clocks per vehicle, one per driver

A small fleet quickly accumulates dates: each vehicle's 2-year calibration and rolling 90-day download, each driver's 28-day card download and card expiry, plus the annual test. A spreadsheet holds them, but only helps if someone checks it every week. Certly turns each date into an automatic email 90, 60 and 30 days ahead (and shorter cycles are simply logged as recurring items), so the calibration appointment is booked before the plaque runs out. Track your equipment the same way — see the LOLER thorough examination intervals — or create a free account and load your fleet in an afternoon.