Editorial Policy - Standards & Methodology | EV Tariff
EV Tariff is an editorial research resource. The same standards apply to every page on the site, whether it is a tariff comparison, a charger review or a grant explainer. This policy documents how we work so readers can hold us to it.
What do we cite and where from?
Every factual claim on this site is traceable to a primary source. In order of preference:
- Regulator / Government - Ofgem default tariff cap announcements, GOV.UK Find a Grant, OZEV scheme T&Cs, HMRC, ASA and CMA guidance.
- Industry bodies - SMMT for registration figures, Zap-Map for public-charger counts, the Distribution Network Operators (DNOs) for regional unit rates.
- Suppliers' own published terms - energy supplier tariff sheets, charger manufacturer specifications, installer pricing pages.
- Industry press - Auto Express, What Car?, the Telegraph EV desk, Fully Charged Show - used for context, not as the primary number.
Forum posts, social-media threads and other sites' interpretations are never the only source for a number. If we use a community sentiment quote or a Reddit summary, it is clearly framed as such.
How do we rank tariffs and chargers?
Tariff rankings are based on the effective off-peak unit rate (p/kWh), the length of the off-peak window, the standing charge, exit-fee terms, and any smart-charging conditions (e.g. 'must use a compatible charger'). Where a tariff varies by DNO region, we publish a regional break-down and rank within that region - not against an averaged national rate.
Charger rankings are based on smart-tariff compatibility (with current published Intelligent Octopus Go and similar API integration lists), real install cost from a representative sample of DNO regions, app reliability (independent reviews and store ratings), warranty length, and OCPP support.
We do not use affiliate commission rates as a ranking factor. If the cheapest or best-rated option doesn't have an affiliate programme, it still wins.
How often do we refresh content?
Tariff pages, grant pages and the pillars they sit under are reviewed:
- Within 48 hours of every Ofgem default-tariff-cap announcement (quarterly).
- Within 48 hours of every UK Budget that touches energy bills, the Climate Change Levy or EV-specific grants.
- Within 7 days of any major energy supplier announcing a new EV tariff or changing an existing one.
- Every 90 days at minimum, even when no external change has triggered an earlier review.
Every page carries a 'last reviewed' date that reflects the latest substantive review - not just a typo fix.