PHEVs Are Coming to Your Forecourt. Are You Ready?

Here’s a stat that should make you sit up.

In May 2026, cars with a plug  -  PHEVs and BEVs combined  -  matched petrol for new car registrations. Both sitting at 41%. For the first time ever.

The UK new car market had its best May since 2019. Private buyers were up 17.2%. And the thing they were increasingly choosing to buy? Plug-in hybrids.

PHEV registrations rose 24% year-on-year. Market share grew from 12% to 14%. Meanwhile, conventional hybrids  -  long seen as the safe middle ground  -  grew just 2% and actually lost share.

As Stuart Masson of The Car Expert put it, PHEVs are no longer just a stepping stone to full electric. They’re becoming the destination.

It’s not hard to see why. PHEVs handle daily driving on electric, then switch to petrol for longer trips. No range anxiety. No need for a home charger. For a huge chunk of the car-buying public, that’s a genuinely compelling deal.

That used stock is coming. The question is whether you’re set up to sell it confidently.

So Why Are Dealers Still Hesitant?

One word: batteries.

Battery condition is invisible. It doesn’t show up on a test drive. And two PHEVs with identical age and mileage can have completely different battery histories  -  one charged every night, one barely plugged in for years.

Mileage won’t tell you. A history check won’t tell you. Only a battery test will.

And here’s the thing  -  the data is actually more reassuring than most dealers expect. A 2025 Battery Performance Index of over 8,000 used plug-in vehicles found average battery State of Health sitting at 95% of original capacity. Most of this stock is fine.

But PHEVs do carry more risk than full BEVs. Research by diagnostics specialist Generational found 4.70% of PHEVs fell below 85% SoH, versus just 1.50% of BEVs. That’s more than twice as likely. The spread of results is wider, and without testing, you simply can’t price or sell with confidence.

Test Before You Price

The good news? Battery testing is now quick, affordable, and accessible to dealers of every size.

AVILOO Flash Test plugs into the OBD port and produces a scored health report, flagging any faulty modules. It covers 95% of EV and PHEV brands, and is already integrated into BCA’s remarketing process  -  vehicles get an A–E grade buyers can act on. MotorCheck offers it alongside history checks too, so the report travels with the car all the way to your retail customer.

One thing worth knowing: the SoH figure the car itself reports isn’t the whole picture. It’s a calculated value from the battery management system  -  it won’t flag cell-level damage or defects. An independent test goes deeper, and that’s what gives both you and the buyer genuine confidence.

A battery health certificate sitting on the windscreen isn’t just protection against returns. It’s a sales tool. For a buyer who’s nervous about PHEVs, it’s often the thing that closes the deal.