3. Mixed assimilated/AETR and GB domestic driving
Source: gov.uk (2025-04-22)

How the drivers' hours rules work when you're driving a passenger carrying vehicle under a mix of the assimilated/AETR and Great Britain rules.

General principles

Many drivers spend some of their time driving under one set of rules and some under another set, perhaps even on the same day.

When working partly under assimilated/AETR rules and partly under GB domestic rules during a day or a week, the following points must be considered (the assimilated rules take precedence over the GB domestic rules):
- the time spent driving or on duty under assimilated/AETR rules cannot count as a break or rest period under GB domestic rules
- driving and other duty under GB domestic rules (including non-driving work in another employment) count as other work but not as a break or rest period under assimilated/AETR rules
- driving and other duty under assimilated/AETR rules count towards the driving and duty limits under the GB domestic rules
3.1 Driving limits

The GB domestic limit (a maximum of 10 hours of driving a day) must always be obeyed. But at any time when actually driving under the assimilated/AETR all the rules on assimilated/AETR driving limits must be obeyed.

3.2 Duty limits

The GB domestic limit (no more than 16 hours on duty between starting and finishing including work other than driving and off-duty periods during the working day) must always be obeyed. But when any assimilated/ AETR driving is carried out, the limit of 13 or 15 hours maximum of duty (determined by the amount of assimilated/ AETR daily rest needed) must always be obeyed. Assimilated/AETR breaks must be taken within these duty periods.

3.3 Rest periods and breaks

All drivers who drive in scope of the assimilated/AETR drivers’ hours rules need to comply with the sector specific working time rules, which have the same rest requirements as the assimilated drivers’ hours rules. Therefore, a driver who drives vehicles in scope of the GB rules on some days/weeks must always comply with assimilated rules rest requirements unless they are classed as an occasional mobile worker. For more information see annex 2 (/guidance/drivers-hours-passenger-vehicles/annex-2-working-time-rules).

Drivers who are occasional mobile workers only need to comply with assimilated/AETR daily rest requirements on days when they drive under assimilated/AETR rules. An assimilated/AETR weekly rest period must also be taken. So where a driver who is an occasional mobile worker works under assimilated/AETR rules in one week and under GB domestic rules the next week (or vice versa), they must take either an assimilated/AETR regular or a reduced weekly rest in the week in which the assimilated/AETR regulated driving takes place. If a reduced weekly rest is taken, compensation will be required by the end of the third week following the week in which the reduced weekly rest is taken.

As it is not permitted to work more than 6 x 24-hour periods (including any non-assimilated/AETR regulated work) between weekly rest periods, drivers who are occasional mobile workers must take an assimilated/AETR compliant weekly rest period prior to undertaking any assimilated/AETR regulated work where any previous non-assimilated/AETR regulated work means the 6 x 24-hour periods would be exceeded.

Where a driver who is an occasional mobile worker takes an assimilated/AETR compliant weekly rest period at least once in any two consecutive weeks, this weekly rest period will also satisfy the requirement to take a 24-hour rest period once a fortnight under the GB domestic rules. If no assimilated/AETR weekly rest period is required in any two consecutive weeks but GB domestic driving takes place, one 24-hour rest period must be taken during those weeks to satisfy the GB domestic weekly rest rule.

3.4 Records

Drivers must follow the general principles (#general-principles) at the start of this section to make sure they record activities appropriately.

Working under assimilated/AETR rules means assimilated/AETR record keeping rules will always apply. This is the case for drivers that meet the definition of an “occasional mobile worker” under the road transport working time rules see Annex 2 (https://www.gov.uk/guidance/drivers-hours-passenger-vehicles/annex-2-working-time-rules).

On any day where a driver carries out a journey covered by both assimilated/AETR and GB domestic rules, the driver must keep records in accordance with assimilated/AETR requirements.

Under assimilated rules, drivers must record all non-assimilated/AETR work (https://www.gov.uk/guidance/drivers-hours-passenger-vehicles/4-tachograph-rules#record-other-work), such as secondary employment, as ‘other work’ using either:
- an analogue tachograph chart
- a digital or smart tachograph printout
- the manual input facility of a digital or smart tachograph
Assimilated/AETR rules also require records are kept for rest days and for annual or sick leave.

There are no separate record keeping requirements under GB domestic rules.

‘Other work’ means all activities which are defined as working time in regulation 2 of the Road Transport (Working Time) Regulations 2005 except ‘driving’ including any work for the same or another employer, within or outside of the transport sector.

If requested, drivers must be able to produce their driver card (if one is held even if it has not been used) and any manual or analogue records for driving which was in scope of assimilated/AETR rules for the current day and driving which has taken place in the previous 28 calendar days.