UK EV salary sacrifice net cost.
Effective monthly cost
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Lease net of IT + NI
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Monthly BIK tax
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The arbitrage that makes EVs so cheap to lease at work
Electric car salary sacrifice is one of the genuinely good deals left in the UK tax system, and it works because of a quirk in how company cars are taxed. You agree to give up part of your gross salary in exchange for a fully maintained EV lease through your employer. Because the lease is paid from pre-tax salary, you escape income tax and National Insurance on that slice of pay. In return you pay a benefit-in-kind charge on the car, but for electric vehicles that charge is tiny, just 3 percent of the car's list price for 2025/26. This calculator nets those two effects to show what the car really costs you each month.
The gap between petrol and electric here is enormous. A conventional car can attract a benefit-in-kind rate of 20 to 37 percent, which usually wipes out the salary sacrifice saving entirely. At 3 percent, the EV charge is almost a rounding error, so the income tax and NI you avoid on the lease dwarfs the tax you pay on the benefit. The rate is legislated to rise gradually, reaching 5 percent later in the decade, so the deal softens over time but remains strong.
A £500 lease for a higher-rate driver
Take a higher-rate taxpayer sacrificing £500 a month of gross salary for an EV with a £45,000 list price, on the 3 percent benefit rate. As a 40 percent taxpayer also saving 2 percent NI on income above the upper earnings limit, every £1 of sacrifice costs them only 58 pence of net pay, so the £500 lease nets down to £290. Against that, the benefit-in-kind is 3 percent of £45,000, which is £1,350 a year of taxable benefit, taxed at 40 percent, giving £540 a year or £45 a month.
| Step | Monthly figure |
|---|---|
| Gross lease sacrificed | £500 |
| Net cost after 40% tax + 2% NI saved | £290 |
| Benefit-in-kind (3% of £45,000, taxed at 40%) | £45 |
| Effective monthly cost | £335 |
| Saving versus a £500 private lease | £165 a month, about 33% |
The chart contrasts what the same car would cost on a private lease against the effective cost through salary sacrifice. A third of the cost simply disappears in avoided tax.
Where the scheme can bite back
Two pitfalls deserve a flag. First, sacrifice cannot take your pay below the National Minimum Wage, so the scheme works best for comfortably paid staff and may be off limits to lower earners. Second, salary sacrifice reduces your gross pay, which can have knock-on effects: it can lower the salary used to assess a mortgage, reduce statutory maternity pay, and trim pension contributions if those are set as a percentage of post-sacrifice salary. For most higher earners these are minor, but they are worth checking before you sign a two or three year lease commitment that is hard to exit if you change jobs.
What happens to the benefit charge as rates rise?
The electric car benefit-in-kind percentage is set to climb a point or two a year, heading towards 5 percent and beyond later in the decade. Even at those higher rates the deal remains attractive compared with petrol, but the saving narrows. Because the BIK rate applied is the rate in the relevant tax year, a multi-year lease will see the charge tick up annually, so model the later years rather than assuming today's 3 percent holds.
Is the saving as good for a basic-rate taxpayer?
It is still positive but smaller. A basic-rate taxpayer saves 20 percent income tax plus their NI on the sacrifice, rather than 40 percent, so the lease nets down less and the benefit charge is taxed at the lower rate too. Set the marginal rate field to 20 percent in the calculator to see the basic-rate outcome, which is why the scheme is marketed hardest at higher earners who extract the most value.