Pool Cars vs Company Cars: Benefit-in-Kind Tax Rules in 2026/27
A genuine pool car creates zero benefit-in-kind for employees. Learn HMRC's strict pool car criteria, the overnight-at-home test, and how car allowances and mileage compare in 2026/27.
A genuine pool car represents one of the few ways a company can provide employees with access to a vehicle without triggering a benefit-in-kind charge. The BIK on company cars is expensive -- a higher-rate taxpayer driving a £40,000 petrol car could pay over £4,000 per year in income tax on the benefit. A properly structured pool car avoids this entirely. However, HMRC's criteria are strict, and the most common error -- allowing employees to take a pool car home overnight -- immediately breaks the arrangement.
The standard company car BIK: what you avoid with a pool car
To understand the value of genuine pool car status, it is worth seeing what BIK would apply if the car were treated as a standard company car.
For 2026/27, the taxable benefit on a company car is:
Taxable BIK = List price x Appropriate percentage
The appropriate percentage depends on CO2 emissions:
- Zero-emission electric: 5%.
- 1-50g/km (EV range 130+ miles): 5%.
- 51-75g/km: 15%.
- 76-94g/km: 19%.
- 100g/km: 23%.
- 125g/km: 28%.
- 150g/km: 32%.
For a £35,000 petrol car emitting 130g/km (30% appropriate percentage):
- BIK = £35,000 x 30% = £10,500.
- Higher-rate taxpayer: income tax = £10,500 x 40% = £4,200 per year.
- Basic-rate taxpayer: income tax = £10,500 x 20% = £2,100 per year.
The company also pays Class 1A NI at 13.8% on the BIK value: £10,500 x 13.8% = £1,449 per year.
A genuine pool car eliminates all of these costs.
The four pool car criteria in detail
All four criteria under ITEPA 2003 s167 must be satisfied for every period of use:
Criterion 1: Available to more than one employee
The car must be made available to multiple employees, not allocated to a specific individual. In practice, this means:
- No dedicated parking spaces for a named employee.
- No individual assigned to the car as "their" car.
- A booking system where different employees can request the car.
Criterion 2: Not ordinarily used by one employee to the exclusion of others
Even if the car is technically available to several employees, if in practice only one person ever uses it, it fails this test. HMRC will look at mileage logs and usage records. If 95% of miles are attributed to one employee, pool car status is at risk.
Criterion 3: Private use is merely incidental to business use
Private use must be incidental -- unavoidably arising from the business trip rather than a deliberate personal journey. Stopping for a coffee on the way to a client meeting is incidental. Driving to the supermarket after a client visit is not. Weekend use is never incidental. Taking children to school in the pool car on the way to the office would be scrutinised closely.
Criterion 4: Not normally kept at or near an employee's home overnight
This is the criterion that most arrangements fail. HMRC interprets "normally" as a pattern of behaviour -- if an employee takes the car home on 3 or 4 nights out of a typical working week, the car is "normally" kept at their home overnight. A very occasional overnight at an employee's home (perhaps once in a year due to an emergency) may be defensible, but regular overnight use at home destroys pool car status.
Car allowances: the tax treatment
Many employers offer a cash car allowance instead of a company car. The employee uses their own private vehicle and receives a monthly allowance to cover costs.
Tax treatment of a car allowance:
- The allowance is taxed as employment income -- subject to income tax and employee NI.
- The employer also pays employer NI on the allowance.
Mileage reimbursement relief:
- Employees using their own car for business miles can claim tax-free reimbursement up to the AMAP rates (45p/mile for first 10,000 business miles, 25p/mile thereafter).
- If the employer pays less than AMAP rates, the employee can claim Mileage Allowance Relief on the shortfall via their self-assessment return or by contacting HMRC.
- If the employer pays more than AMAP rates, the excess is taxable income.
Example: Employee receives £400/month car allowance (£4,800/year, fully taxed). Drives 8,000 business miles per year. Employer reimburses 25p/mile = £2,000. AMAP-approved rate = 45p/mile = £3,600. Employee can claim Mileage Allowance Relief on £1,600 shortfall at their marginal tax rate.
Mileage allowance vs company car vs pool car: a comparison
| Arrangement | Employee BIK | Employer NI on benefit | Employee convenience |
|---|---|---|---|
| Pool car (genuine) | Zero | Zero | Shared; must book |
| Company car (petrol, 130g/km, £35k) | ~£10,500 | ~£1,449/year | Dedicated vehicle |
| Car allowance (£4,800/year) | Full allowance taxed as income | Employer NI on allowance | Own car used |
| Electric company car (5% BIK) | £35k x 5% = £1,750 | £241/year | Dedicated EV |
For most companies, the genuine pool car arrangement is the most tax-efficient -- but it requires real operational changes (shared booking, cars kept on site) rather than simply relabelling an existing arrangement.
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Open Income Tax calculatorFrequently asked questions
What is a pool car for tax purposes?
A pool car is a company vehicle that satisfies all the pool car criteria under ITEPA 2003 s167. A genuine pool car creates no benefit-in-kind (BIK) for any employee who uses it. The car is available for multiple employees, not kept at any individual employee's home overnight, is used only for business purposes (with incidental private use), and is not ordinarily used by one employee to the exclusion of others.
What are the HMRC criteria for a genuine pool car?
HMRC will only accept pool car status if ALL of the following conditions are met: (1) the car is made available to and used by more than one employee; (2) it is not ordinarily used by one employee to the exclusion of others; (3) any private use by an employee is merely incidental to the business use; (4) the car is not normally kept at or near any employee's home overnight.
What is 'incidental private use'?
Incidental private use means use that is incidental to the business purpose -- for example, stopping at a shop briefly on the way to or from a business trip. It does not include deliberate diversions for personal purposes, using the car on weekends for personal trips, or taking the car home in the evening and using it for personal journeys. HMRC interprets 'incidental' very narrowly.
What is the overnight-at-home test?
The single most important pool car criterion is that the car must not normally be kept at or near an employee's home overnight. If an employee takes a pool car home in the evening even once a month, HMRC will typically conclude the car fails the pool car test for that employee. The car should be kept on company premises (a car park, depot, or office) overnight.
What BIK applies if a car fails the pool car test?
If a car fails to meet the pool car criteria, it is treated as an ordinary company car and the standard BIK rules apply. The taxable BIK is based on the car's list price multiplied by an appropriate percentage based on CO2 emissions. For a petrol car with 130g/km emissions, the BIK percentage is around 31% in 2026/27. The employee pays income tax on the BIK value.
What is a car allowance and how is it taxed?
A car allowance is cash paid to an employee to cover the cost of using their own vehicle for work. The allowance is taxed as employment income -- subject to income tax and National Insurance. The employee can claim AMAP mileage relief (45p per mile for first 10,000 miles, 25p thereafter) if the employer's reimbursement rate is below these approved amounts.
What is the AMAP rate for business mileage in a private car?
The Approved Mileage Allowance Payment (AMAP) rates for 2026/27 are 45p per mile for the first 10,000 business miles and 25p per mile thereafter. These are the maximum amounts an employer can reimburse tax-free. If an employer pays less, the employee can claim Mileage Allowance Relief on the shortfall.
How does HMRC scrutinise pool car claims?
HMRC conducts compliance checks on pool car arrangements as part of PAYE audits and enquiries. Common red flags include: mileage records showing regular start and end points at employees' home addresses, cars kept at employee homes overnight based on GPS tracking or fuel records, one employee accounting for the large majority of the car's use, and no credible log of multi-user usage.
Are electric pool cars treated differently?
No -- the pool car criteria apply equally to electric vehicles. A genuine pool car that happens to be electric creates zero BIK just like any other genuine pool car. However, the BIK rate for electric company cars (that fail the pool car test) is currently 5% in 2026/27, making a personal company EV relatively low-BIK compared to petrol or diesel alternatives.
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