COUNCIL taxpayers are being urged to check they are paying the correct amount after it emerged that as many as 400,000 people have been overcharged because they have been placed in the wrong tax band.

Council-tax bills are set to jump by an average of 3.9% in April, with the average band D bill increasing by £52 to £1,374, according to a survey by the Chartered Institute of Public Finance and Accountancy.

The latest rise means that council-tax bills have doubled since Labour came to power. In 1997 the average Band D tax was £689.

However, many households are paying more than they need to because their homes have been wrongly valued.

The mistake was revealed in a government document that ministers had tried to conceal.

A spokesman for the Department for Communities and Local Government said: “Anyone who has evidence that they are in too high a band can request a review.

“If successful, they will also qualify for a rebate.”

Moneysavingexpert.com, which offers a step-by-step guide to checking if you are in the correct band, said that some people have received as much as £4,000 by reclaiming overpayments going back as far as 1993, when council tax was introduced.

Every household is placed in a council-tax band which determines how much you pay. There are eight of these bands, from A to H, and which one your property comes under is based on its value in 1991.

Those in the top band, H, pay three times as much as those in band A, while most people are in band D.

Many properties have been inaccurately banded because estate agents, who carried out the valuations on behalf of the government, priced them incorrectly. Martin Lewis, who runs Moneysavingexpert, said: “Many were valued by estate agents who simply drove past in a car and allocated a band.

“The valuing system has more holes in it than Swiss cheese.”

If you think you are paying too much, the first thing to do is check how your banding compares to your neighbours’.

To do this, go to the Valuation Office Agency website (www.voa.gov.uk) if you live in England and Wales, or the Scottish Assessors Association (www.saa.gov.uk) in Scotland.

These allow you to check your council-tax band and those of any of your neighbours in similar houses for free.

If you find you’re in a higher band than your neighbours in a similar property, you may have a case.

A useful second check is to find out the value of your property in 1991 as this is what your band is based on.

Follow the instructions in www.moneysavingexpert.com/council to do this.

Compare the price with the 1991 bands that are also listed on the website.

If both the above steps show you’re in the wrong band, then you may have a good chance of getting a refund.

Banding appeals can be made online at the Valuation Office Agency, in England, or the Scottish Assessors Association, in Scotland.

Alternatively you can write to your local authority.

However, there are dangers to challenging your banding.

For a start. your council will carry out a “reassessment”, and if it decides your property should be in a higher band your bill could go up.

Homeowners who have extended or converted their home are particularly at risk.