UK: should you fix your energy tariff?

Ofgem’s price cap sets a ceiling on standard variable tariffs, reviewed every 3 months — it’s not a fixed price, it moves with wholesale costs. Fixed-rate deals lock your unit rates for a set term (commonly 12 months), sometimes above and sometimes below the current cap depending on where wholesale prices are heading. Fixing makes most sense when the cap is expected to rise; staying variable makes sense when it’s expected to fall, since fixed deals often carry an exit fee if you leave early.