The research showed that in St Albans there were 24 disclosures of unpaid tax per 100,000 population last year.
Edinburgh was second on the list with 23, followed by Slough with 19.
London (15 per 100,000), Bristol (14) and Oxford (14) also featured in the top ten.
Andrew Snowdon, partner at UHY Hacker Young, says: “Tax avoidance is not restricted to super-rich neighbourhoods of London such as Kensington and Chelsea. A lot of middle-income earners have been sucked into tax schemes over the last two decades.
“Some very normal commuter belt towns like Slough are minor hotspots for admitting unpaid tax which may reflect their residents’ views on the rising tax burden in areas like income tax and stamp duty land tax.
The top UK towns and cities for the highest number of individuals admitting unpaid tax revealed – disclosures per 100,000 population
Source: UHY Hacker Young
Disclosing tax planning schemes
UHY Hacker Young said that postcodes with high numbers of disclosures tend to be wealthier with residents that have complex tax affairs. These individuals are more likely to make a disclosure.
HMRC’s crackdown on the use of tax planning schemes by high net worths (HNWs) may have driven the number of disclosures in some areas by prompting individuals to come forward. If a taxpayer comes forward voluntarily then HMRC is likely to be more lenient when issuing penalties.
England & Wales had 11 disclosures per 100,000 population on average last year, with a total of approximately 6,380 disclosures made overall (does not include areas where there were fewer than five disclosures last year).
“Coming forward to make a tax disclosure is a far better option then burying your head in the sand as many people last year realized,” said Snowdon. “HMRC is prone to take a much more lenient approach if a disclosure is made unprompted. A prompted disclosure could result in fines of up to 100% of the tax owed.
“As HMRC continues to beef up its compliance teams and data resources, there is increasingly nowhere to hide for those with unpaid tax bills.”
“Making a disclosure it almost always the best way to deal with an irregular tax position but it’s important to seek professional advice before doing so in order to get the best possible settlement.”
The accountancy firm said HMRC has put significant resources into investigating the affairs of HNWs in recent years.
HMRC has several specialist teams dedicated to the crackdown, including the offshore corporate and wealthy unit, which launched over 800 investigations last year.