Npower has become the latest power firm to reduce gas prices this year, but the cuts do not apply to its online tariffs.
Some two million households will see bills fall by 7% on 26 March, yet Npower has 3.7 million energy customers so many won't see cuts as the reductions mainly apply to the company's standard tariff.
There are cuts to a small number of expensive online tariffs that have not been available to new customers for years, to bring them in line with other web-based deals. They are Sign Online 4, 5 and 6.
Npower says the decrease means standard customers will typically save between £54 (where gas and electricity is provided by Npower) and £62 (gas only) a year.
It says it's not cutting most online bills as its tariffs are already "competitively priced".
Eon revealed yesterday its gas prices will fall by 6% at the end of the month, while Scottish & Southern Energy (SSE) announced a 4% - 9% gas price cut last week, to take effect on 29 March (see the Eon and SSE price cuts MSE News stories).
Last month, British Gas cut gas prices by an average 7% (see the British Gas price cut MSE News story).
Time to switch?
Regardless of what the quartet say, BG's, Eon's, Npower's and SSE's tariffs will not necessarily be the cheapest, while those on their standard deals will almost certainly be paying too much as the best prices are online.
The energy market is complicated so determining which is the cheapest provider depends on where you live and how much power you use.
Households can sometimes cut their bills by hundreds by doing a comparison of the tariffs available (see the Compare Gas & Electricity and Get Cashback guide).
Martin Lewis, MoneySavingExpert.com founder, says: "As we said when British Gas cut its prices, energy companies are like sheep, they bleat and follow the herd. We've now seen four of the big six drop their prices and it'd be a surprise if the others didn't follow pretty quickly.
"Yet the savings to be made here are paltry compared to those most people can make by ditching and switching to the cheapest online tariffs.
"Only a fraction of homes are on these, yet many could cut their bills by £100s by comparing, ditching and switching."
Further reading/Key links
Slash energy costs: Cheap Gas & Electricity
Your rights: Fight Energy Direct Debits
Capped tariff help: Is your Cap/Fix ending soon?
Boiler protection: Boiler Cover