Martin Lewis has issued three pieces of advice for everyone on what has been dubbed "meter reading day".
Energy providers have been struggling to keep up with the volume of traffic to sites on Thursday as millions scrambled to submit meter readings ahead of the April 1 deadline.
Among the energy companies that have reported technical difficulties on the 'submit a meter reading' sections of their websites are; British Gas, EON, EDF Energy, Shell and Scottish Power - though some customers say they've been able to submit their meter readings on mobile apps instead. For the latest on the situation follow our live blog here.
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Martin Lewis is a former financial journalist turned Money Saving Expert who shares free advice on how to save money. In a video posted to his Twitter account, the journalist said he isn't surprised that energy firms have gone down today.
He said: "Surprise surprise, many of the energy firms are struggling to cope with demand even though they had plenty of notice that this was coming and lots of people are in panic."
He encouraged people not to panic and offered some words of wisdom of what to do if your energy firm isn't accepting meter readings online or via the phone and who actually needs to submit a meter reading.
Why we should be submitting meter readings
Martin Lewis has been explaining that the reason for submitting a meter reading today is to avoid paying more for energy you might have used when the tariffs were cheaper.
Speaking on ITV, he said: "If you're on a price capped tariff - which is 75% of people - your rate is going to go up 54% tomorrow. If you don't do a meter reading, let's say you did your last meter reading a month ago and you do your next meter reading in a month, then you have a two-month period where in the middle the energy price goes up. They are going to look at your usage across that period and they are going to proportion some for when it was cheap, and some for when it's expensive."
Who should and shouldn't send a reading
From April 1 the price cap in England, Scotland and Wales goes up by 54%, so who actually needs to submit a reading? It's people who are on price capped tariffs and people who do not have smart meters or prepayment meters. If you're on a fixed tariff you do not need to submit a meter reading because you won't face a change happening to you at the moment. "If you're not on a price cap including anybody in Northern Ireland you don't need to do this," he said.
Those who have smart meters also don't need to submit a meter reading ahead of the price cap increase as your meter does this automatically. Martin Lewis said: "I would still take a picture of your meter today just in case of a future dispute, you might want to email it to yourself so you have timestamped proof."
What to do if your energy provider's site has crashed
Martin Lewis said: "If your firm's website isn't accepting a meter reading, don't panic, this is just a way of protecting yourself from them estimating your usage at the higher rate.
"If you were to do it tomorrow, or the day after, or the day after that, just doing it around now reduces the wiggle room for a problem with estimates. So a day or two out isn't the biggest panic in the world.
"If you can't send it online and phonelines are too busy some of them do allow you to email a photo of your meter to count as your meter reading."
