You need to log each work-related journey for a continuous 12-week period which is representative of your annual work-related kilometres travelled.
Record the odometer reading in your car on the first day of the 12-week period.
Each day, record every work-related journey during the 12-weeks showing the odometer reading when you start your work-related trip and the odometer reading when you finish that trip.
Record the odometer reading in your car on the last day of the 12-week period.
Congratulations! You can now determine your business-use percentage and keep it for the next five years.
A work-related journey is one of the below:
Directly between two separate workplaces
From your normal workplace to an alternative workplace that is not a regular workplace while still on duty, and back to your normal workplace or directly home
If your home was a base of employment – you're required to start your work at home then travel to a workplace to continue your work for the same employer
If you had shifting places of employment – you regularly work at more than one site each day before returning home
From your home to an alternative workplace that is not a regular workplace for work purposes, and then to your normal workplace or directly home.
if you need to carry bulky tools or equipment that your employer requires you to use for work but you can't leave at your workplace (for example, an extension ladder or a cello) – the tools or equipment are bulky, meaning that because of the size or weight they are awkward to transport and can only be transported conveniently by motor vehicle.