Experts are urging everyone to submit meter readings for gas and electricity to their supplier as soon as possible, to show exactly how much energy has been used ahead of Ofgem’s price cap increasing from April 1.
This will prevent firms from estimating usage and potentially charging for energy used before April 1 at the higher rate.
Going forwards, billpayers should also send regular meter readings - ideally on the same date each month - to prevent their supplier potentially overcharging as they move into the summer months and use less heating.
Many appeared to have taken heed of the calls on Thursday, with energy websites faltering with the influx of customers submitting their readings.
Gillian Cooper, head of energy policy at Citizens Advice, said: “We’d recommend sending meter readings to your supplier ahead of the price cap rise on 1 April. This means your energy company will have an accurate picture of your usage before higher rates come in."
How much will prices rise by?
The energy price cap for those on default tariffs who pay by direct debit is rising by £693 from £1,277 to £1,971 from 1 April.
Prepayment customers will see a bigger jump, with their price cap going up by £708, from £1,309 to £2,017.
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The regulator was forced to hike the energy price cap to a record £1,971 for a typical household as gas prices soared to unprecedented highs.
Fuel poverty charity National Energy Action (NEA) warned the cost of heating an average home has now doubled in 18 months, leaving 6.5 million households unable to live in a warm safe home across the UK.
NEA chief executive Adam Scorer said: “Quality of life for millions of people will plummet. Warm homes, cooked food, hot water, clean clothes – all cut back or cut out. Debt will spiral. Physical and mental health will suffer.
“This energy crisis is about to bite down hard on those least able to cope. Charities like NEA will try to pick up the pieces for those in greatest need. It will be a near impossible task.”
But I can't enter my reading online, what do I do?
Customers reported issues logging in to supplier websites including British Gas, EDF, E.On, SSE, So Energy and Octopus Energy from early on Thursday.
Scottish Power, for example, told customers it had increased its website capacity by 500% but still could not cope with the "unprecedented demand."
But Energy UK, the trade body for the industry, urged people not to worry if they were unable to submit a meter reading ahead of Friday.
It said: “Most suppliers are offering alternative options such as submitting at a later date, and different methods to send meter readings such as text, social media and email.
“This demonstrates the scale of the problem and how worried people are about high prices, which is why we have been asking government to intervene to provide further support to consumers.”
Finance specialist Martin Lewis suggested a number of steps people can take if their providers site has crashed, including:
Taking a photo of the reading accompanied by something that showcased the time and date in case of a future dispute
Attempt to submit readings online later when websites are functioning as normal
Check to see if suppliers offer alternative ways of sending off reading
And, if you have a smart meter, your readings will be sent off automatically.
What help is available?
Chancellor Rishi Sunak pledged to “take the sting out” of the price rises, promising that all 28 million households in Britain would get a £200 up-front rebate on their energy bills from October.
The government will provide the cash for this, but it wants the money back so will hike bills by £40 per year over the next five years from 2023 to recoup its cash.
How much support will households get? Consumer Editor Chris Choi explains
If all goes to plan, wholesale energy prices will drop so households can pay back what they owe, without a major rise in bills.
Some energy company insiders worry that while good in principle, the policy is too reliant on falls in global gas prices.
But experts are not sure this will happen, at least not soon.
Goldman Sachs has already warned that prices in the gas market are likely to remain at twice their usual levels until 2025.
Mr Sunak also promised a £150 council tax rebate for homes in bands A to D, something he said would cover around 80% of homes in England.
He also promised £144 million to councils to support vulnerable people.
I’m worried by these rises, what other support is available?
If you are on a low income or claim pension credit, you may eligible for Warm Home Discount through your supplier.
This cuts bills with a one-off discount of £140 at some point between September and March - which will be take off your bill rather than paid directly to you.
You must contact your supplier to confirm your eligibility and apply, though the number of discounts a supplier can give is limited.
If you fall behind on payments, there are suppliers that offer grants. Citizen's Advice Bureau (CAB) lists suppliers that offer grants:
If none of these companies supplies your energy, you can still apply for a grant though British Gas Energy Trust as you do not need to be a customer.
Meanwhile, Simple Energy Advice offers a tool on its website to locate grants available in your specific area.
Your local council may also provide various grants.
Prices will vary according to where you live
While the rise in the energy price cap affects everyone, there will be slight variations in the overall cost around the UK.
This can be impacted by how much an energy company sells in your area, how much it buys from generators, and the different charges imposed on the supplier by the local distribution networks.
If you live in a remote area with a limited number of households using energy, for example, suppliers will try to recuperate the cost of supplying by charging more for energy in this area.
The most expensive areas of the UK for energy are typically Merseyside and the south of Wales. while the cheapest are in the north of Scotland and the East Midlands.