Octopus' Estimated Annual Cost on bills is misleading.

However

Just received first bill on the new regime (for all of three days!). All the tariffs, usages and so on are correct (apart from one slightly odd rounding on their part) but the headline "Your estimated annual cost" is frighteningly high because my calculations show that they haven't taken into account the Energy Price Guarantee reduction. My understanding it's in place for more than a full year, so the reduction should be fully applied to any annual estimates.

Taking into account my current credit balance, I've done the sums over 12 months, using only Octopus' figures. Octopus say I should be paying £154.34; I say I should be paying £154.69. I think that's close enough to be spot on! Both Octopus and I haven't taken notice of nor have estimated the three-monthly tariff hikes which will change the figures; nor that the £66/£67 grant payments stop after six months which will require another recalulation.

So, don't just divide by 12 the Estimated Annual Cost at the head of your bill - bill amounts are alarming enough as it is.