From April 1, Welsh residents will pay an extra £175 million in council tax, thanks to a property re-banding exercise taken on behalf of the Assembly government.

More than 430,000 properties in Wales have moved up at least one council tax band and many have jumped more than one band.

Individual homeowners may be shocked to find sudden, hefty rises in their council tax bills. If your property has shifted from band D to band E, you will pay an extra £242 per year, an increase of 28%.

So here's the good news. Hometrack, a property focused on-line data services company, is to launch its council tax re-banding verification (CTRV) service which it believes will help Welsh council tax-payers ensure they are not penalised by inaccurate bandings.

Residents using the service will pay an initial £9.95 to analyse the probability that their new banding is fair, as determined by Hometrack's database.

Then if the tax-payer is confident, there is the evidence for a full appeal against the Valuation Office Agency which carried out the revaluation last year. Home owners pay another £29.95 to access the evidence.

For that price, Hometrack's CTRV service will provide comparable evidence of unsurpassed accuracy to support residents' appeals.

The CTRV utilises Hometrack's database of more than six million property records across the UK to undertake online valuations using various data sources including: a database of surveyors' valuations, Land Registry, Ordnance Survey, the Hometrack Index as well as socio-economic data from consumer analysis firm, CACI.

According to Hometrack's CEO, Mark Wither-spoon, his system's technology is highly coveted by the Valuation Office Agency itself.

He said: "The Valuation Office is due to use our programme when it carries out its revaluation in England in 2007. It wasn't ready in time for the Welsh operation last year.

"There will always be slight flaws if you are evaluating the 1.3 million properties in Wales but while the Valuation Office examined and then made assumptions on one property from every 30, we can narrow our error margin to as if we were examining one house in every six.

"To be fair to the Valuation Office, they are relying on citizens who feel aggrieved to appeal because they want to get it right as much as anyone.

"Our online service is open to anyone who feels there are obvious discrepancies in their street."

For further information on the Hometrack service, refer to www.hometrack. co.uk