A home charger left open will happily power up anyone who plugs in — here’s how to make sure only your paying guest can charge, and how to bill them for it.
Last reviewed 6 September 2026 · ~7 minute read
If you’re a host offering EV charging at your rental, hotel or B&B, you’ve probably noticed the meter ticking over faster than expected. The short version: most home chargers vend electricity to anyone who plugs in, they don’t know who your guest is, and they certainly don’t bill anyone. This guide walks through why free charging happens and the practical ways to stop it — from the clumsy to the properly managed.
You added a charger to make your property more attractive, and it worked. But somewhere between “nice amenity” and “why is my electricity bill up £120 this month” the maths stopped adding up. A modern EV battery holds 60–100 kWh, and topping one up from near-empty can cost the equivalent of a week’s worth of household electricity in a single overnight session. Do that a few times a month, across back-to-back bookings, and a generous gesture quietly becomes a running cost you never agreed to.
The good news is this is a solved problem. Let’s look at why it happens, what it really costs, and the options in front of you — honestly, including the ones that don’t involve us.
Why guests charge for free in the first place
It’s rarely malicious. A standard OCPP home charger is, by default, an open tap. Plug in, and it starts delivering power. There’s no gate asking “are you allowed to use this?” and no till taking payment. So three things tend to happen:
- Guests assume it’s included. If a charger is sitting on the driveway and nobody said otherwise, most people reasonably conclude it’s a free perk, like the kettle or the Wi-Fi.
- The charger can’t tell who’s who. Your booked guest, last week’s guest, a neighbour, or a passer-by who spotted a socket — the hardware treats them all the same.
- Nobody’s being billed. Even a guest happy to pay has no way to, so the cost defaults to you.
And it’s not only your guests. An unsecured charger on a driveway or in a car park is an open invitation for neighbours to “just top up quickly” or for opportunists to piggyback between your bookings. If it vends to anyone, eventually it vends to everyone.
The real cost of “just absorbing it”
Let’s put numbers on it. At typical domestic rates, a full charge of a mid-to-large EV can run to £15–£30 (or more on a peak tariff). One charging guest a week is comfortably £60–£120 a month straight off your bottom line — before you count the neighbour who’s discovered your driveway. Over a year, that’s the price of a decent appliance, gifted to strangers.
Absorbing it also removes your ability to plan. Electricity is one of the few guest costs that scales with something you can’t see or control — the size of their battery and how empty it was on arrival. If you want a sense of what fair pricing looks like, our guide on how much to charge guests for EV charging breaks down the common models. The point stands either way: “free forever” isn’t a pricing strategy, it’s a leak.
Option 1: Unplug or physically lock the charger
The most obvious fix is a physical one — flip the breaker between stays, fit a lockable cover, or unplug the unit. It works, in the narrow sense that a charger with no power can’t give electricity away.
But it’s a blunt instrument. You become the on/off switch, which means being on-site (or trusting a cleaner) to enable it for each arrival and disable it after each departure. Guests who are meant to charge find a dead socket and message you at 11pm. And you’ve turned a selling-point amenity into a source of friction. It also does nothing about billing — you’re still giving the electricity away, just to fewer people. Worth avoiding, too, is the temptation to leave out a 3-pin “granny” lead as a compromise; we cover why in our note on the risks of 3-pin granny chargers for guest charging.
Option 2: The charger maker’s own app
Most chargers ship with a manufacturer app that can lock the unit and require the owner to start a session. Better than an open tap — but built for a single household, not a hospitality business.
- It ties access to your account, not the booking. Typically you’re the one starting each charge, or handing out credentials you’d then need to rotate.
- It rarely bills. Most owner apps stop at on/off and energy stats. There’s no automatic “charge this guest £X” at checkout.
- It’s per-brand. Run two properties with two charger brands and you’re juggling two apps and two workflows.
Fine for a personal driveway. Clunky the moment you’re doing it for paying guests on repeat.
Option 3: An access-and-billing layer over your existing charger
This is the approach that actually fits a hosting business, and it’s where Guest Charge sits. Rather than replacing your hardware, it manages the OCPP charger you already own and adds the two things the charger and its own app lack: controlled access and automatic billing.
Only your current guest can start a session
Each booking gets a private link or QR code. Your guest taps it, starts their charge, and that’s it. The charger won’t vend to a random plug-in, because starting a session requires the access you issued for this stay. Neighbours and passers-by are out; last week’s guest is out.
It’s switched off between stays
Scheduling means the charger is only live during a booking window, so there’s no gap between guests where the socket is quietly open. You don’t have to remember to flip anything — it follows the calendar.
Billing happens automatically
You choose how to charge: a flat fee per stay, by the kWh actually used, or a simple per-day rate. The guest is billed automatically, so you’re not chasing anyone or doing sums after checkout. If you go the per-kWh route, it’s worth understanding the metering and billing rules that apply to hosts so you charge on a sound footing.
Setting expectations with guests still matters
Technology handles the enforcement, but a line in your listing and your welcome message does a lot of quiet work. Say clearly that EV charging is available and how it’s priced — “charging is available at the property, billed per kWh via a link we’ll send” — and you convert the awkward surprise into an expected, welcome amenity. Guests are overwhelmingly happy to pay a fair rate for the convenience; they just need to know it’s there and how it works.
Transparency also protects your reviews. Nobody likes a hidden cost, and a guest who’s told the arrangement up front has no cause for complaint when the charge appears.
Why “just trust them” doesn’t scale
For one favourite guest, informal works fine. But hosting is a numbers game — different guests every week, cleaners and turnovers in between, sometimes multiple properties. Trust doesn’t remember to switch the charger off, doesn’t stop the neighbour, and doesn’t itemise a kWh. Every booking is a fresh chance for the informal arrangement to leak, and the leaks compound.
The aim isn’t to police your guests. It’s to make the fair outcome the automatic one — the guest charges easily, you’re paid fairly, and nobody else gets a free ride — without you having to think about it each time.
The bottom line
A charger left open will charge anyone, for free, at your expense. Unplugging it kills the amenity; the maker’s app half-solves access but not billing. The durable fix is a thin layer over the charger you already own that lets only your current guest charge, keeps it off between stays, and bills automatically. Keep offering the perk — just stop paying for other people’s cars.
Turn your charger into a managed, paid amenity — using the hardware you already have.
This article is general guidance for accommodation hosts and doesn’t constitute legal, tax or energy-billing advice. Electricity costs and metering requirements vary by region and tariff — check the rules that apply where your property is located before setting guest pricing.