The heat will be on energy giant SSE on Wednesday when it reveals how much money it is making for the first time since a winter price hike.
SSE, formally known as Scottish & Southern Energy, recently increased prices by an average of 9% in a move which will affect five million electricity customers and 3.4m gas customers.
Customers will be looking at interim results closely amid anger that firms are leaving customers out in the cold while they continue to turn in huge profits.
Investors will also be watching to see if the unseasonably chilly autumn has boosted consumption.
In May, SSE posted a 2% rise in annual profits to £1.3 billion but the surplus from domestic operations was down 21% to £271.7m as it battled higher costs and falling consumption.
British Gas owner Centrica will also be in the spotlight on Thursday, having announced it will increase its prices by an average of 6% on November 16.
The UK's biggest energy supplier, which is due to post a trading update, came under fire in July for making residential operating profits of £345 million in the space of six months, equivalent to £1.9 million a day.
Vodafone investors will find out tomorrow if an initiative to keep UK customers until the widespread roll out of 4G technology has struck a chord.
It comes after a year which has seen revenues fall as the mobile phone giant loses ground to rivals offering unlimited deals.
Vodafone will have to wait until the spring to launch its 4G products after EE, formally known as Everything Everywhere, got the go-ahead to offer services on the network, which has speeds up to five times faster than 3G.
Vodafone's new "4G phone promise" offers customers the chance to bring an eligible phone into any store and have 70% knocked off their remaining contract, in exchange for taking on a 4G device.
But while it battles in the fiercely competitive UK market, Vodafone is likely to be buoyed by earnings from its stake in America's largest mobile phone network.
The City expects revenues in its interim results on Tuesday will be £21.8 billion, down from £23.5 billion for the same period last year, while underlying profit will fall from £7.5 billion to £6.8 billion.
The Newbury-based firm's performance has been hit by recessions in Spain and Italy, while the fees it can charge for connecting mobile calls are being reduced in markets such as the UK.
Paralympics sponsorship and investment in cheaper own-brand products has helped supermarket Sainsbury's take market share from rivals Tesco and Morrisons.
The country's third largest grocer was the star performer in recent data from researcher Kantar as its share of the market jumped to 16.8% while Tesco and Morrisons saw their positions weaken.
And it is expected to build on its strong run in half-year results on Wednesday when it unveils a 5% rise in underlying pre-tax profits in the six months to £371 million.
The group has benefited heavily from its sponsorship of the London 2012 Paralympics as well as its Brand Match scheme and higher investment in its own labels.
It continued to put struggling rival Tesco into the shade as it revealed a 1.9% rise in like-for-like sales excluding fuel but including VAT in its second quarter to September 29.
TalkTalk will hope to put its troubled past behind it tomorrow as the broadband and television firm reveals a return to customer growth.
It had been haemorrhaging customers but analysts believe this will have been reversed in its second quarter after it confirmed it had returned to net growth in June.
In addition, TalkTalk will reveal underlying earnings, excluding television, more than doubled to £348 million in the first six months of the year to September 30.
Andrew Lee, an analyst at Goldman Sachs, who upgraded his recommendation on TalkTalk to buy from hold, said: "We believe TalkTalk offers attractive top-line growth potential, compounded by one of the best self-help opportunities in the sector."