Scottish Power said it was forced to raise bills because it "can no longer continue to shield our customers" from cost increases.
Neil Clitheroe, Scottish Power's chief executive for Energy Retail & Generation, said the company's costs have risen across the board for buying gas and electricity, supplying it to homes and dealing with customers.
"I find it very difficult having to increase our prices," Clitheroe said. "Each of these costs have been rising over the course of this year, and we have now reached a point where we can no longer continue to shield our customers from these increases."
Scottish Power said that over a million of its 3.2 million customers will not be affected by its price rises because they are on fixed or capped tariff deals.
The company has customers throughout the UK but is especially popular in Glasgow, Edinburgh, Merseyside and North Wales.
ScottishPower said the average duel fuel bill for its customer will increase by £113 per year due to increasing costs.
The price rises are primarily driven by the:
- 7% increase in wholesale energy costs
- 11% rise in the costs of delivering energy to customers' homes
- 16% increase in the costs to support compulsory social and environmental schemes
ScottishPower will raise the average prices of its duel fuel bulls by 8.6%, gas by 8.5% and electricity up 9%.
Independent fuel retailers are urging drivers to lobby their MPs to demand a freeze on fuel tax.
They've teamed up with the pressure group "The Taxpayers' Alliance" to highlight just how much of what we pay at the pump goes straight to the Government.
Petrol station owners say high prices are hurting them just as much as their customers, as Ryan Dollard reports.
The TaxPayer's Alliance is ramping up pressure on the government to cut duty on fuel.Read the full story ›
The TaxPayer's Alliance (TPA) is ramping up pressure on the government to cut duty on fuel. Together with the Petrol Retailer's Association (PRA) they are setting up stands on 5,000 independent forecourts around the country today to ask motorists to lobby local MP's.
Sixty pence in every pound spent on petrol or diesel in the UK goes directly to the treasury.The UK has the highest tax component of unleaded petrol in the EU.
Campaigners against high fuel tax will be on forecourts across the region this morning to tell customers how much their petrol costs and how much money is going to the Treasury. Over 5,000 stands will be set up across the country.
Businesses have welcomed the announcement by the Chancellor that fuel duty will not rise by 3p in August.
It could ultimately benefit consumers, by preventing an increase in the cost of transporting essential goods.
Businesses in the region have welcomed the Chancellor's decision to postpone a planned 3 pence rise in fuel duty.
It had been due to go up in August, but will now be frozen until the end of the year.
ITV Business Club member Chris Reay, Managing Director of Reay's Coaches in Carlisle says it's given their firm a big boost in challenging times.