"We really should keep a trip log." The sentence comes up regularly in businesses, usually right after a fine has turned up that nobody can attribute to anyone. And almost as regularly, the person saying it means something different from what a trip log means for tax purposes.
It pays to separate the three things that get mixed up here. Two of them you can solve with clean booking documentation in an afternoon. The third is a topic of its own.
Three questions that have nothing to do with each other
1. Who had the vehicle? This is the keeper question. When a fine arrives, a scratch turns up, or an accident has to be cleared up, you need a defensible link between vehicle, period, and person. That does not require a trip log. It requires a traceable booking record.
2. How many kilometres were driven? This is the operations question: service intervals, leasing mileage limits, allocating costs to departments. Mileage at pickup and return is enough, captured by the person who is sitting in the vehicle anyway.
3. How is the private-use benefit taxed? This is the tax question, and only here does "trip log" mean a trip log in the strict sense. Anyone who wants to avoid flat-rate taxation of private use has to document every single trip completely, promptly, and tamper-proof, including date, mileage at start and end, destination, purpose, and business contact. A calendar entry is not enough for that, and neither is a notebook filled in after the fact.
The key point: for pool vehicles, most businesses only need questions 1 and 2 answered. Pure pool vehicles used exclusively for business purposes create no private-use benefit, so the trip log discussion does not apply to them at all.
What a booking record has to deliver
To keep the first two questions permanently answered you need less than you might think, but it has to be reliable:
- Vehicle, period, and person in one record, not spread across calendar, chat, and key rack.
- Mileage at pickup and return, captured in the same step as the booking. Anything that requires a second form or a second app does not get filled in.
- Cost center or site, if you want to allocate costs internally.
- Exportability. The data only helps if you can get it out as a table when you need it.
The practical trick is to put these fields into the booking form itself instead of chasing them afterwards. Ten seconds spent at booking time saves the office the reconstruction, which in practice does not work anyway.
Where an electronic trip log starts
If employees are allowed to use a company car privately and flat-rate taxation is to be avoided, there is no way around a tax-compliant electronic trip log. Those systems plug into the OBD port or are installed permanently, record every trip automatically via GPS, and are protected against later changes.
A booking system is not that and does not try to be. It documents reservations, not distances driven. If you need both, you run both, but separately and each with its own legal basis. Location data is a far deeper intrusion than an occupancy plan; why that matters especially when dealing with a works council is covered in our article on GDPR and booking data.
The pragmatic route
For the vast majority of fleets with pool vehicles, the sensible order looks like this:
- Collect bookings in one place so that vehicle, period, and person always belong together.
- Make mileage a required field in the booking form.
- Set a retention period long enough for fines and damage claims, then delete.
- Only then check whether individual vehicles with private use additionally need an electronic trip log.
Our page for fleets shows how to set up steps 1 and 2 in ten minutes, and for the organizational side of the pool model, see Managing pool vehicles. Free for 30 days, no payment details.