3. Mixed assimilated or AETR and Great Britain domestic driving
Source: gov.uk (2025-04-22)

How the drivers' hours rules apply when driving a goods vehicle under a mix of the assimilated or 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 or 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 or 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 or AETR rules
- driving or other duty under assimilated or AETR rules count towards the driving and duty limits under 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 assimilated or AETR rules all the rules on assimilated and AETR driving limits must be obeyed.

3.2. Duty limits

GB domestic limit (no more than 11 hours on duty in a 24-hour period) must always be obeyed. But when any assimilated or AETR driving is carried out, the limit of 13 or 15 hours maximum of duty (determined by the amount of assimilated or AETR daily rest needed) must always be obeyed. Assimilated or AETR breaks must be taken within these duty periods.

3.3. Rest periods and breaks

All drivers who drive in scope of assimilated or 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 rest requirements in the assimilated rules unless they are classed as an occasional mobile worker. For more information see Annex 2 (/guidance/drivers-hours-goods-vehicles/annex-2-working-time-rules).

Drivers who are occasional mobile workers only need to comply with assimilated or AETR daily rest requirements on days when they drive under assimilated or AETR rules. A weekly rest period under the assimilated rules or AETR rules must also be taken. So where a driver who is an occasional mobile worker works under assimilated or AETR rules in one week and under GB domestic rules the next week (or vice versa), they must take either a regular or a reduced weekly rest in the week in which the assimilated or 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 work that is not regulated by assimilated rules or AETR rules) between weekly rest periods, drivers who are occasional mobile workers must take a weekly rest period prior to undertaking any assimilated or AETR regulated work where any previous work not regulated by assimilated rules or AETR rules means the 6 x 24-hour periods would be exceeded.

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 or AETR rules means assimilated or AETR record keeping rules will always apply in addition to GB domestic record keeping rules. This is the case for drivers that meet the definition of an “occasional mobile worker” under road transport working time rules (/guidance/drivers-hours-goods-vehicles/annex-2-working-time-rules).

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

Under assimilated rules, drivers must record all non- assimilated and non-AETR work (https://www.gov.uk/guidance/drivers-hours-goods-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 and AETR rules also require records are kept for rest days and for annual or sick leave.

‘Other work’ means all activities which are defined as working time in working time rules, 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 assimilated AETR records, including the driver card if held, for the current day and the previous 28 calendar days, as well as any GB domestic records.