Money Saving expert Martin Lewis has warned bill payers who pay for their energy by direct debit.
Martin warned people could end up paying 8% more if cancelling the direct debit in favour of separate payments.
The presenter was giving financial advice on an episode of This Morning on Tuesday when he received a call from one customer who claimed they were planning on cancelling their regular payments.
OVO customer Claire said their plan was to instead pay on the app, as energy bill costs continue to soar.
But the financial expert quickly warned Claire this could be a bad idea, affecting your credit score and end up costing you more.
During the Money Show Live section on the ITV show, which was focusing on debt, Martin said: "I would caution you against it.
"As long as you tell OVO you're cancelling your direct debit and changing your mode of payment then it won't affect your credit score because you're not missing any payments and you're in credit.
"The first thing you want to do is get your monthly direct debit the right amount."
To do this, Martin recommended visiting his website's handy online calculator, which helps people work out if they're paying the right amount.
He added: "You then take it to OVO and discuss if your direct debit is too high.
"The whole point of the direct debit system is use more in winter, less in summer and you pay somewhere in the middle.
"The reason I say I don't want you to cancel your direct debit is if you move into payments into receipt of bills.
"That is what most people do when they cancel direct debits. That is around 8% more expensive.
"You will pay 8% more on top of the already huge rates to pay your bills."
Martin urged Claire to tell OVO if they were planning to cancel the direct debit.
This is because he advises customers who are looking to cancel to look into switching onto a variable direct debit.
While this system is not offered by OVO themselves, Martin states that most other energy firms allow their customers to switch to the alternative payment method.
He said: "If you don't like what you're paying on direct debit and you want to take control of that and only pay for what you use.
If you can, you switch to variable direct debit which is the same price as monthly direct debit so you don't have the 8% increase.
What that means is you either have a smart meter or you do meter readings each month and then they just charge you on how much you use.
"Of course that means your bills are going to be really, really high in the winter and much lower in the summer so you have to manage your own cash flow."
