Car Allowance vs Company Car UK 2026 — Which Is Worth More After Tax?

Every year, thousands of UK employees face the same question: take the car allowance or choose from the company car list? The right answer depends on your tax rate, the car's CO2 emissions, whether you charge at home, and how many business miles you cover. Get it wrong and you could easily be £2,000–£4,000 worse off each year.

This guide works through the full tax treatment of both options in 2026/27, provides detailed worked examples across petrol, diesel, and electric vehicles, and tells you exactly when a cash allowance beats a company car — and when it does not.

How Car Allowances Are Taxed

A car allowance is simply additional salary. It goes through payroll and is subject to:

• Income tax at your marginal rate (20%, 40%, or 45%)
• Employee NI at 8% (on earnings between £12,570 and £50,270) or 2% above £50,270
• Employer NI at 15%

There is nothing special about a car allowance from HMRC's perspective — it is fully taxable cash. A £5,000 allowance for a basic-rate taxpayer produces approximately £3,450 after tax and NI (income tax £1,000, NI £550). For a higher-rate taxpayer, the same £5,000 leaves only £2,880 in hand (income tax £2,000, NI £120 at 2%).

Using Your Own Car for Business: AMAP

If you receive a car allowance and use your own car for business miles, you can claim Approved Mileage Allowance Payments (AMAP) from your employer — or, if your employer does not pay the full rate, you can claim the shortfall as a tax relief via Self Assessment.

If your employer pays 25p/mile and you drive 15,000 business miles:

• AMAP entitlement: (10,000 × 45p) + (5,000 × 25p) = £5,750
• Employer pays: 15,000 × 25p = £3,750
• Shortfall claimable: £2,000 — tax relief worth £400 at basic rate or £800 at higher rate

High-mileage allowance drivers can significantly improve the allowance's value through this mechanism.

How Company Car Benefit in Kind Tax Works

Company car tax — formally called Benefit in Kind (BiK) tax — is calculated on the P11D value of the car (its list price including options and delivery, excluding first-year registration fee) multiplied by a CO2-based percentage, then taxed at your marginal income tax rate.

Annual BiK tax = P11D value × CO2% × marginal income tax rate

Employer NI is also due on the BiK: P11D value × CO2% × 15% — this is a cost to the employer, not to you directly, but it affects what employers are willing to offer.

CO2 Percentages for 2026/27

Diesel cars (non-RDE2 compliant) add a 4% surcharge, though most modern diesels registered after September 2018 are RDE2 compliant and avoid this.

Worked Example 1: £5,000 Allowance vs £30,000 Petrol Car

Scenario: Higher-rate taxpayer (income £55,000), employer offers either a £5,000 cash allowance or a £30,000 petrol car with 130g/km CO2.

Car Allowance After Tax

• Gross allowance: £5,000
• Income tax (40%): −£2,000
• Employee NI (2% above £50,270): −£120
• Net cash received: £2,880

Plus AMAP fuel expenses if doing business miles.

Company Car Tax Liability

• P11D value: £30,000
• CO2 at 130g/km: 27% (2026/27)
• Taxable BiK: £30,000 × 27% = £8,100
• Income tax at 40%: £8,100 × 40% = £3,240/yr additional tax
• Monthly additional tax: £270

The company car costs you £3,240/year in extra income tax. The net benefit you receive (a free car, fuel card if included, servicing, insurance) must be worth at least that over £3,240 plus the £2,880 net allowance foregone — a total of £6,120/year — for the company car to make sense purely on a cash basis.

In practice, once you factor in running costs a £30,000 petrol car would typically cost £4,500–£7,000/year to run privately (insurance ~£800, servicing ~£400, fuel ~£2,000+ at 10,000 miles, depreciation ~£3,000–£4,000). The company car can be well ahead here — but much depends on whether the employer provides a fuel card.

Worked Example 2: £5,000 Allowance vs £35,000 Electric Car

Electric vehicles carry a BiK rate of just 4% in 2026/27 — a deliberate government incentive. The benefit is striking.

Electric Company Car Tax Liability

• P11D value: £35,000
• BiK%: 4%
• Taxable BiK: £35,000 × 4% = £1,400
• Income tax at 40%: £1,400 × 40% = £560/yr additional tax
• Monthly additional tax: £47

For a higher-rate taxpayer, the total tax cost of a £35,000 EV is just £560 per year — less than half of what a £5,000 cash allowance would cost in income tax alone. The EV company car wins decisively on pure tax arithmetic.

The EV BiK Escalation

The government has confirmed EV BiK rates will increase to prevent a permanent cliff edge:

Even at 7% in 2029/30, a £35,000 EV generates only £2,450 of taxable BiK — still significantly lower than most petrol or diesel alternatives. EV company cars remain attractive through the decade.

Worked Example 3: £5,000 Allowance vs £30,000 Petrol Car — Basic-Rate Taxpayer

Scenario: Basic-rate taxpayer (income £35,000), same vehicle.

Car Allowance After Tax

• Income tax (20%): −£1,000
• Employee NI (8%): −£400 (assuming within basic-rate NI band)
• Net cash: £3,600

Company Car Tax

• BiK: £30,000 × 27% = £8,100
• Tax at 20%: £1,620/yr additional tax
• Monthly: £135

Here the company car costs £1,620/year more in tax. The net allowance of £3,600 must be weighed against the value of getting a free car. For a basic-rate taxpayer with access to a good company car list, the company car typically wins — the employer is effectively funding the vehicle almost entirely.

When the Allowance Beats the Company Car

The car allowance typically wins when:

1. You drive very high business mileage — AMAP at 45p/mile (45p versus HMRC's advisory fuel-only rates of ~15p/mile for petrol) generates significant untaxed income. At 20,000 business miles: (10,000 × 45p) + (10,000 × 25p) = £7,000 AMAP entitlement — all tax-free if employer pays it.

2. The company car list has only high-emission vehicles — if your only option is a 170g/km petrol SUV with a 35% BiK rate, the tax cost is punishing.

3. You already own a reliable, low-depreciation car — if your own car costs £2,000/yr to run and you get a £5,000 allowance after tax, you net £3,000+.

4. You are a basic-rate taxpayer choosing between the allowance and a modest petrol car with moderate BiK — the free car may not be worth the tax.

HMRC Advisory Fuel Rates

If your employer provides a company car with a fuel card, HMRC's advisory rates (from June 2026) for private fuel reimbursement are approximately:

If private fuel is provided free, a separate fuel benefit charge applies: the fuel benefit multiplier (£27,800 in 2026/27) × CO2% × your marginal tax rate. For a 27% CO2 car: £27,800 × 27% = £7,506 additional BiK. For higher-rate taxpayers this costs £3,002/yr — typically making a free fuel card poor value unless you drive very high private mileage.

VAT Considerations

Employers cannot reclaim input VAT on cars bought for mixed business/private use (the standard case for company cars). They can reclaim 50% of VAT on lease payments. None of this directly affects your take-home, but it explains why many employers are reluctant to put high-value cars on the company car scheme.

For electric cars, employers can reclaim input VAT on commercial charging costs and on dedicated business charging infrastructure.

Making the Decision

Use this quick checklist:

• Is an EV available on the company car list? → Almost always take the car (4% BiK)
• Are you a higher-rate taxpayer with a petrol/diesel choice? → Calculate the BiK tax carefully; allowance often wins above 25% CO2
• Do you drive >15,000 business miles/year? → Allowance + AMAP likely better
• Does the employer offer a fuel card? → Add fuel BiK calculation before deciding
• Is the car list restricted to high-emission vehicles? → Take the allowance

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Use our Take-Home Pay Calculator to model the after-tax impact of a car allowance on your salary, and our P11D Benefit Calculator to calculate the exact annual tax cost of any company car before committing to a choice.