The headline is only one line of the bill.

Start with electricity you buy for everything in the home, then add the car once. The useful comparison is the annual total under each set of rates, using the same energy demand. An attractive night price tells you little about a household that uses most electricity during the day.

Copy annual household consumption from your bill or meter history. For this worksheet, that figure must exclude the EV. If your existing annual total already includes the car, subtract the car's metered home-charging energy before entering it. Do not add the battery capacity on top of an electricity-meter reading: charging losses are already part of the metered energy.

Only count energy that gets the cheap rate

Use a realistic amount that can move into the eligible window. Some arrangements discount the whole home during defined hours; others credit eligible vehicle charging separately. An app-controlled charging slot does not by itself establish the rate for the rest of the house. Confirm the exact arrangement before entering figures.

This calculator compares a single-rate baseline with a proposed two-rate tariff. It does not model dynamic half-hourly prices, EV-only credits, solar export, batteries or a change to your gas tariff. Use the supplier's own comparison for those arrangements, and include any gas-price difference in your wider decision.

Keep the comparison fair. Use rates from the same dated quote and include applicable taxes consistently. Add exit charges or unavoidable fees separately. Check meter, vehicle or charger eligibility, fixed-period terms and what happens if the smart integration stops working.

Ofgem explains unit rates, standing charges and regional differences. The calculator and comparison workflow are original EVDeal tools. Example inputs below are invented to explain the method; they are not current market rates.

Two quotes with the same charger can describe different work. Ask each installer to price the same cable route, charger position and electrical scope. A remote estimate based on photographs may still depend on a survey; ask what could change the final price and when you will be told.

Keep three totals: charger hardware, installation work and any continuing charge. Record the tax treatment on each quote. A lower hardware price is not a saving if fitting, cable length or required electrical work is missing.

Make the exclusions visible

Ask for included cable length and the charge for extra metres, trenching, access work, wall repair and any consumer-unit or supply changes. Ask who checks the home's electrical suitability, handles any required network notification or approval, and supplies the completion documents. These are questions for a qualified installer, not a DIY checklist.

If a grant is mentioned, ask which scheme, who applies, when approval is needed and what you pay if the application fails. For the renters and flat owners scheme, the official application route starts with an OZEV-authorised installer's quote. Eligibility and scheme rules must be checked for your situation; a discounted advert is not approval.

Take the same photos and measurements to both installers, but redact account details and unnecessary personal information. Keep the final agreed scope alongside the invoice.

1. Is it a discount, or a useful link?

EVDeal lists discount codes, affiliate links and information resources. A provider listing without a code is a route to information; it does not establish a special EVDeal price. A source-check date records a review, not a guarantee that an offer is still available today.

Before leaving the site, note the exact product, variant and claimed saving. On the provider's page, check eligibility, minimum spend, excluded items, expiry, delivery and whether another promotion can be combined. Apply the code before paying and compare the complete basket with the equivalent option elsewhere. Do not buy an accessory you do not need merely to reach a discount threshold.

2. Does the recurring fee earn its place?

A public-charging membership earns back a monthly fee only through eligible energy that actually receives the lower price. Divide the monthly fee in pounds by the price reduction in pounds per kWh to find the break-even energy. For an invented £8 fee and a 10p/kWh reduction, the energy-only break-even is 80 kWh per month. Below that, the fee exceeds that energy saving.

Count the networks and sites you will use, not all your charging. Check roaming prices, billing periods, cancellation rules and whether parking or idle charges apply. Use EVDeal's existing public-charging comparison with your own rates; it already includes a monthly pass cost.

3. Can you reconcile the actual transaction?

For charging, keep the quoted rate, charger ID, start and finish times, delivered kWh and the final receipt. A bank's pending authorisation and a settled payment are different records; compare the final bill before assuming you paid twice. Use the operator's official receipt and support route for an unexplained difference.

UK government guidance requires the maximum charging price to be displayed in pence or pounds per kWh, including connection or other charging fees. Parking can be a separate matter: read the site's signs as well as the app. The official public-chargepoint guidance explains pricing transparency and the scope of payment requirements. It does not make every charger contactless.

Keep the evidence useful. Share a redacted receipt or quote when seeking help. Do not publish a payment-card number, account identifier, home address or vehicle-access code. EVDeal's comparison tools do not need those details.