There is no universal winner. A tracker tariff can save a flexible household £300/year; a fixed tariff can save a predictable household their sanity. The trick is knowing which you are.
The shortlist
Fixed tariffs lock you in at today's wholesale assumption. Tracker tariffs move with a benchmark — typically the day-ahead wholesale price plus a margin. In April 2026 the spread between the cheapest fixed and the median tracker is about 3p/kWh on import.
Three real households
- EV owner, overnight charging: tracker or overnight-EV tariff wins by £380/year.
- Fixed 9-to-5 schedule, no solar: fixed tariff saves ~£90/year and zero admin.
- Solar + battery, arbitrage-friendly: tracker with a low minimum import rate wins by £420/year.