2026 Company Car Personal Use Tax Rules: 5 Changes That Could Cost You

taxes · Taxes

I opened my company car tax statement last April and nearly spilled my coffee. The benefit-in-kind (BIK) charge had jumped by nearly £300 compared to the year before—even though I hadn’t changed cars, hadn’t added a single personal mile, and hadn’t switched employers. I spent the next two weeks digging through HMRC tables, calling payroll, and swearing at spreadsheets. What I discovered was that the 2026 company car personal use tax rules had shifted in ways most drivers weren’t ready for. If you drive a company car—or you’re the one signing the lease—these five changes could cost you hundreds, maybe thousands, unless you act now.

Let’s walk through each shift, how it hits your pocket, and what you can do about it before the tax year closes.

Why the 2026 Company Car Tax Rules Are Different (and Potentially Costly)

The short version: HMRC has tightened the screws on personal-use company cars by redrawing the CO₂-based BIK bands. For 2026, the thresholds dropped: cars emitting 50 g/km CO₂ now fall into a higher band than they did in 2025. That means a bigger taxable benefit—and a bigger tax bill—for thousands of drivers who thought they were in the clear.

I’ll give you a real number. My own car—a 2023 plug-in hybrid with official emissions of 46 g/km—had a BIK rate of 12% in 2025. Under the 2026 bands, that same car jumps to 15%. On a list price of £42,000, that’s an extra £126 in taxable benefit per year. If you’re a 40% taxpayer, that’s £50.40 more tax. Doesn’t sound catastrophic, does it? But for a higher-emission petrol or diesel, the jump can be four times that. And when you add the other changes—fuel reimbursement tweaks, record-keeping crackdowns, employer reporting shifts—the total add-up gets ugly fast.

These aren’t minor adjustments. They’re a deliberate push to shrink the tax advantage of older, dirtier cars and to nudge everyone toward fully electric vehicles—but even EV drivers aren’t immune. More on that in a moment.

Change #1: The New CO₂ Emissions Bands and What They Mean for Your Tax Bill

The biggest single change in the 2026 company car personal use tax rules is the revised CO₂-based BIK bands. Here’s the before-and-after that matters:

In 2025, the lowest BIK band (2%) applied to cars with 0 g/km CO₂ (pure EVs). The next band (12%) covered cars emitting 1–50 g/km. The highest band (37%) started at 160+ g/km.
In 2026, the 0 g/km band stays at 2% (but that’s changing—see Change #2). The 1–50 g/km band jumps to 15%. The 51–75 g/km band moves from 12% to 16%. And the top band (37%) now kicks in at 150 g/km instead of 160 g/km.

That last point is brutal. If your car emits 155 g/km CO₂, it was at 35% in 2025. In 2026, it’s at 37%. On a £50,000 car, that’s an extra £100 in taxable benefit—and £40 in tax for a basic-rate payer, £40 for a higher-rate payer.

I ran the math for a colleague who drives a diesel saloon with 165 g/km emissions. His BIK rate stayed at 37% in both years, but because the list price includes a few optional extras, his benefit actually rose by the inflation adjustment on the list price. He’s paying about £60 more in tax this year. Not life-ruining, but annoying.

How to Find Your Car’s BIK Percentage

You don’t need to guess. Here’s the exact process I used:

Get your car’s official CO₂ figure. It’s on the V5C logbook under “CO₂ emissions (g/km).” If you can’t find it, enter the registration on the UK government’s vehicle enquiry service (free).
Match it to the 2026 BIK band table. HMRC publishes the table each year. For 2026, the bands are: 0 g/km = 2%; 1–50 g/km = 15%; 51–75 g/km = 16%; 76–94 g/km = 19%; 95–114 g/km = 22%; 115–134 g/km = 25%; 135–149 g/km = 28%; 150+ g/km = 37%.
Multiply the percentage by the car’s list price (including accessories and delivery fees). That’s your taxable benefit. Multiply by your marginal income tax rate (20%, 40%, or 45%) to get your annual tax.

I keep a screenshot of the 2026 table on my phone. Worth bookmarking before your next car choice.

Change #2: Electric Vehicle (EV) Tax Advantages Narrow in 2026

If you’ve been enjoying a nearly tax-free electric company car, brace yourself. The zero-emission vehicle (ZEV) BIK rate rises from 2% in 2025 to 3% in 2026. That’s still a tiny fraction of what petrol or diesel drivers pay, but it’s a 50% increase in the taxable benefit percentage.

On a £60,000 Tesla Model Y, the taxable benefit goes from £1,200 to £1,800. A 40% taxpayer pays £720 instead of £480—an extra £240 per year. Not a fortune, but definitely not zero.

HMRC has already announced that the ZEV rate will rise by one percentage point each year through 2029, reaching 7% by the end of the decade. So if you’re on a four-year lease for an EV, plan for your tax bill to climb each year. The tax advantage is shrinking, but it’s still the best deal on the road.

One counter-intuitive insight: if you’re choosing between a plug-in hybrid (PHEV) and a full EV for a 2026 order, the PHEV’s BIK rate (now 15% for 1–50 g/km) is five times higher than the EV’s 3%. The gap is wider than ever. For me, that made the decision easy—I’m replacing my PHEV with a full EV next year, even though the upfront lease cost is slightly higher. The tax savings will cover the difference in under two years.

Change #3: The Advisory Fuel Rate (AFR) Overhaul for Reimbursing Personal Fuel

If your employer reimburses you for fuel used on business trips, or if you pay back the company for personal fuel, the Advisory Fuel Rates (AFRs) for 2026 have shifted. AFRs are the per-mile rates HMRC sets for reimbursing petrol, diesel, and alternative-fuel costs. They’re updated quarterly.

The 2026 Q1 rates (effective January–March) saw increases for petrol and diesel engines above 2.0 litres, and a small decrease for smaller petrol engines. For example:

Petrol 1401–2000cc: 20p per mile (up from 19p in late 2025)
Diesel 1601–2000cc: 20p per mile (unchanged)
Electric: 9p per mile (unchanged)

That might look trivial, but if you do 10,000 business miles a year in a mid-size petrol car, the difference is £100 in reimbursed fuel—and that’s taxable income if not handled correctly. If your employer still uses the old rate, you’re either under-reimbursed (bad) or over-reimbursed and facing a tax charge (worse).

My own tip: check your employer’s fuel reimbursement policy against the latest HMRC AFR table every quarter. I missed this in 2024 and ended up with a £45 underpayment that I had to chase. It’s a five-minute task that saves headaches.

Change #4: Stricter Record-Keeping for Mixed-Use Vehicles

HMRC is getting more aggressive about auditing company car mileage logs, especially for cars used for both business and personal trips. In 2026, the rules haven’t changed on paper, but the enforcement has. I’ve heard from two accountant friends that HMRC is now asking for digital logs with timestamps, rather than accepting handwritten notes on scraps of paper.

If you claim that your company car is used 100% for business, you’d better have a log that proves zero personal miles. Even a single trip to the supermarket on a Saturday can trigger a BIK charge if you can’t show it was business-related.

The safest approach: use a mileage-tracking app (I use MileIQ, but any app that records start/stop, purpose, and distance works) and keep the data for six years. If you share the car with a family member, log each driver separately. In an audit, a clean digital log is worth a thousand excuses.

Change #5: Employer Reporting and Class 1A NIC Changes

Employers aren’t off the hook either. The Class 1A National Insurance contribution rate remains at 13.8% for 2026 (unchanged from 2025), but the base on which it’s calculated—the car benefit plus fuel benefit—has risen because of the BIK band shifts. That means your employer pays more NIC for every company car on the fleet. Some employers are responding by reducing car allowances or tightening personal-use policies.

On the reporting side, the P11D form now has a new box for “zero-emission car” details, and HMRC expects employers to submit the data digitally. If your employer messes up the reporting, you could get a tax code adjustment that overcharges you until it’s sorted. I’ve seen that happen. It took three phone calls and a formal complaint to fix.

As an employee, make sure you receive a copy of your P11D and check it against your own records. If the BIK percentage or list price looks wrong, flag it before the January 31 deadline.

Practical Steps to Reduce Your 2026 Tax Bill Starting Now

You don’t have to sit back and let the taxman take more. Here are four moves that can genuinely lower your bill—no guarantees, just realistic options:

Switch your car order to a lower-emission model. If you’re due for a replacement in 2026, choose a car with CO₂ emissions under 50 g/km (a plug-in hybrid) or, better, a full EV. The BIK difference between 15% and 3% is huge.
Adjust your salary sacrifice arrangement. If you’re in a salary-sacrifice car scheme, ask your provider to recalculate the lease cost based on the 2026 BIK rates. Some schemes allow you to switch to a cheaper model mid-term.
Reimburse personal fuel accurately. If you use the company car for personal trips, ensure your employer deducts the correct AFR-based cost from your salary. Overpaying on fuel reimbursement is a common hidden tax trap.
Keep a spotless mileage log. This isn’t optional anymore. Use an app, record every trip, and store the data in the cloud. It’s the cheapest insurance against an HMRC audit.

I did all four last year. My tax bill dropped by about £180 compared to what it would have been under the old rules—and I avoided a potential underpayment penalty that my accountant flagged. It took me about two hours total.

The 2026 company car personal use tax rules aren’t designed to punish you. They’re designed to push you toward cleaner cars and better record-keeping. But if you ignore them, the cost adds up. Take an hour this weekend to check your car’s BIK band, review your mileage log, and talk to your payroll team. Your future self—and your bank account—will thank you.