You are required to show which vehicle you are driving every time you make a logbook entry. Additionally, every time you drive under a different TSL/different vehicle you need to make a new entry.
Pro tip: Read our article 'Add Vehicles In Your Logmate App'
To record a change in the vehicle you are driving in your digital logbook, do the following:
Start Other Duty - this mode is still considered working but indicates that you are doing a non-driving task
Wait at a minimum of 1 minute and then click the Drive button
Select the new Vehicle and press the blue Save button in the top right corner
