Company car · HMRC · Business vs private use
Company car business vs private mileage: when does HMRC treat a journey as private?
A company car can be tax-free only in limited business-only situations. The practical challenge is proving what the car was actually used for — especially because ordinary commuting normally counts as private use.
For company-car tax, “private use” is broader than leisure driving. HMRC treats any use that is not business travel as private use. In particular, a normal journey between home and a permanent workplace is ordinarily private travel.
1. Why business and private mileage matter for a company car
A company car made available to an employee is normally treated as available for private use. That can create a taxable company-car benefit. HMRC provides an exception where private use is genuinely prohibited and does not happen in practice.
This makes the journey record more than an expenses tool. It can help an employer see whether the actual use of a business-only vehicle matches the written policy.
2. HMRC's two-part test for a business-only company car
Test 1
Private use is prohibited
The terms on which the car is made available must genuinely prohibit private use.
Test 2
No actual private use
The vehicle must not in fact be used privately during the relevant period.
Both parts matter. HMRC guidance says an intended ban on private use is not enough if private driving actually occurs.
3. Ordinary commuting normally counts as private use
This is the point most likely to surprise drivers. Travel from home to a permanent workplace is normally ordinary commuting, and HMRC treats ordinary commuting as private use for company-car benefit purposes.
There can be fact-specific exceptions, but a normal commute should not be silently labelled as business mileage just because the vehicle belongs to the employer.
4. A mileage log helps with actual use — but does not prove everything
A clean mileage record can show that the journeys captured during the period were business journeys rather than private journeys. But it cannot by itself prove that the car was never available for private use or that the employer had an effective contractual prohibition.
For Tesla journey capture, see the business mileage tracker. Keep the classification evidence separate from the tax calculation: EV BIK is covered in the electric car company car tax guide.
HMRC's public guidance tells employers providing cars for business journeys only to tell employees not to use them privately and check that they do not. DriveQuery can support that checking process by making the journey history reviewable.
Turn raw Tesla journeys into a reviewable company-car record
5. What should a useful company-car journey record contain?
For a practical audit trail, keep the factual trip data together with the reason for the journey. A useful record includes:
- Date and time
- Start and end locations
- Distance
- Journey purpose
- Business / ordinary commute / private classification
- Driver confirmation where the purpose is not obvious
DriveQuery can collect available route, time and distance data automatically through the Tesla connection. The driver or employer should still confirm the purpose where tax treatment depends on context.
Example: what a review-ready month can look like
| Date | Route | Purpose | Class | Miles | Status |
|---|---|---|---|---|---|
| 3 Aug | Home → permanent office | Normal workday | Private commute | 18 | Confirmed |
| 3 Aug | Office → Client A | Client meeting | Business | 27 | Confirmed |
| 4 Aug | Home → Project site | Temporary assignment | Business* | 41 | Workplace rule checked |
| 6 Aug | Home → New destination | Not entered | Unclassified | 12 | Needs review |
*Illustrative only. A journey to a project site is not automatically business travel; the temporary-workplace conditions still need to be satisfied.
6. Company Tesla mileage reimbursement is a separate question
Whether a company car creates a taxable benefit and how an employee is reimbursed for business electricity are different issues. For a company Tesla, HMRC's Advisory Electric Rates can be used for qualifying business mileage reimbursement.
If private use is available and the car benefit applies, see the Tesla company car tax guide and the BIK calculator.
See the company Tesla business mileage and Advisory Electric Rate guide →
7. Pool cars have their own exemption rules
Pool cars are another distinct HMRC category. Broadly, they must be shared for business use and normally kept at the employer's premises, with private use restricted to what the pool-car rules allow. A vehicle does not become a pool car merely because more than one employee drives it.
If a fleet relies on pool-car treatment, route history can still be useful operational evidence, but the full HMRC pool-car conditions need to be considered separately.
8. How DriveQuery can reduce the admin
The hard part is not calculating a percentage. It is reconstructing hundreds of journeys months later. DriveQuery can record Tesla journeys continuously, learn recurring categories and place uncertain routes in a review queue.
Example month
1,184 miles recorded
Every journey captured from the Tesla history.
Business
1,071 miles
Confirmed client and inter-site journeys.
Needs review
3 journeys
New routes requiring a purpose before the report is closed.
DriveQuery workflow
Record every journey. Review the exceptions.
A business-only policy is only useful if actual use follows it. Make the Tesla trip history searchable, categorised and easy to review before payroll, tax or fleet teams need the evidence.
Frequently asked questions
Does commuting in a company car count as private use?
Normally yes. HMRC treats ordinary commuting between home and a permanent workplace as private use for company-car benefit purposes.
Can a company car be exempt from the car benefit charge if it is business only?
Potentially, but both conditions must be met: the terms on which the car is provided must prohibit private use and the car must not actually be used privately.
Is a mileage log enough to prove there is no company-car benefit?
No. A mileage log can support evidence of actual journeys, but HMRC also looks at whether private use was genuinely prohibited and whether the vehicle was available on those terms.
Is travel to a temporary workplace private mileage?
Not necessarily. A qualifying temporary-workplace journey can be business travel, while ordinary commuting to a permanent workplace is normally private travel. The detailed travel rules depend on the facts.
Are pool cars automatically exempt?
No. HMRC has specific conditions for pool cars, including how they are shared, used and normally kept. Simply sharing a car does not automatically make it a qualifying pool car.
Is company-car business mileage the same as using my own car for work?
No. The journey may still need to qualify as business travel, but the reimbursement and tax frameworks are different. Own-car mileage normally uses the AMAP framework, while a fully electric company car can use HMRC's Advisory Electric Rates for qualifying business electricity reimbursement.
Sources: HMRC – meaning of private use and business travel, HMRC – private use prohibited and none occurs, HMRC – no actual private use, GOV.UK – company cars: what's exempt and GOV.UK – reporting company cars to HMRC.
Make company-car use reviewable.
DriveQuery is being built to capture Tesla journeys automatically, separate business from ordinary commuting and private travel, and leave only uncertain trips for review.