Martin Lewis issues warning to anyone who bought their house before 1991

Money expert is urging people across the UK to check if they might be owed thousands of pounds back in council tax.

That's because despite years of campaigning on the issue, various governments in England and Scotland have left council tax valuations unchanged since 1991, meaning thousands if not millions of people may be paying too much for their property.

And with the average Band D property costing £2,171 a year in , moving up or down a band could mean the difference between moving up to the cheaper C band could mean savings of hundreds of pounds.

But warned that those who bought their house before 1991 needs to try to work out how much their house is worth based on 1991 prices and make two checks before they challenge their band because it could backfire.

Speaking on the latest episode of The Martin Lewis Money Show Live on ITV1 and ITVX, Martin said: "These are the checks you need to do. The check and challenge system is my system, it is not an official system, this is my way to give you a level of safety.

"Nothing here is perfect, I cannot guarantee perfection.

"The first check is the neighbours check. Is your hand higher than neighbours in nearby preferably identical or similar homes?

"You don't need to ask them, you can simply go on and check your band at gov.uk for England and Wales.

"If it looks like you're in a higher band than many of your neighbours in similar homes, the second check, which can't be used in evidence, is your safety check.

"What was your house worth in 1991? Because it is still those 1991 prices that dictate what band you are in."

then added: "So if you bought your house after 1991, it's quite easy you just find the price and the sale date.

"If it was earlier than that, then you go onto those property websites like Zoopla and Rightmove and you try to find a similar property that's been sold since that point that you're going to be able to track down.

"And then you want to back calculate its value in 1991 prices.

"And there are free check and challenge calculators online that will convert this for you."

Martin Lewis then warned that this is not something to proceed with lightly because of the risk it could end up pushing you or your neighbours' bills UP instead of down.

He added: "I would only look at challenging my banding if I passed clearly both tests.

"That's because you can't ask for your band to be lowered. You can ask for your band to be looked at. And that means, well, if you only pass the neighbours check, if could mean it's not you who's in too high a band, it's all your neighbours in too low a band, and when you ask for this, their band goes up, which will not make you very popular."