A TOTAL of £37million of council tax went uncollected in Wales last year, latest figures have shown.
Meanwhile, total council tax arrears reached a new high of £84 million.
In Wrexham the unpaid council tax due totalled £4,683,000 as of the end of March.
In Flintshire the total was £2,844,000.
However, both are close to the Wales average for successfully collecting the tax.
In Wrexham 96.5 per cent of tax was collected from 2011 to 2012, in Flintshire 97.8 percent. The Wales average is 96.7 per cent.
Janet Finch-Saunders AM, Shadow Minister for Local Government, said: “It is grossly unfair that families in Wales are facing higher council tax bills to subsidise the minority who refuse to pay their share.
“In challenging economic times, councils should be working harder to collect unpaid taxes to limit increases in bills for hardworking and law-abiding taxpayers.
“While it may be unrealistic to expect councils to collect 100 per cent council tax, total arrears now stand at a massive £84million.
“Welsh ministers need to work constructively with local authorities to encourage sharing best practice so councils can raise their collection rates and use the savings to reinvest in frontline services and reduce council tax bills for all.”
Mark Owen, head of finance at Wrexham Council said: “Wrexham Council has collected £48m of the £49.7m billed during 2011/12. It is important to realise that the collection continues and that within three years of the bills being raised over 99 per cent of the outstanding council tax will have been collected.
“Wrexham Council will pursue outstanding arrears and are extremely reluctant to write off these amounts.”
A spokesman for Flintshire Council said the authority’s 97.8 per cent collection rate was the highest ever achieved in Flintshire and put the council in the top three local authorities in Wales.
The spokesman said: "Out of the £60.5 million raised in council tax during 2011/12, the council had collected £59.2 million by March 31 2012.
“We will continue to collect monies owing in a consistent and fair manner.”