The Revenue thinks it can retrieve hundreds of millions of pounds more
HM Revenue & Customs (HMRC) will launch a second campaign next year to get tens of thousands of people to pay tax on money hidden in offshore bank accounts.
The "offshore disclosure facility" will target account holders in about 300 banks and building societies which have offshore operations.
The first campaign last year, aimed at customers of the big five high street banks, raised £450m from 45,000 people.
The Revenue says some tax dodgers it uncovered last year will be prosecuted.
"The intention of the new facility will be to provide an opportunity for account holders to inform us of their own accord of any unpaid tax or duties and to settle their debts in a similar way to the original offshore disclosure facility," said a Revenue spokesman.
The incentive for people to come forward will be a limit on the fine they might face, plus the threat of prosecution and much higher fines if they do not confess.
Theoretically, the Revenue can fine miscreants up to 100% of the unpaid tax.
Last year, the penalty was capped at just 10% to encourage confessions, but this time around it will be higher, probably between 20% or 30% of the tax due.
Ronnie Ludwig, of accountants Saffery Champness, said this did not give sufficient encouragement to people to pay their taxes.
"The previous deal was not sufficiently generous to encourage people to come forward, so I anticipate a smaller response this time" he said.
The Revenue's latest move will not be a tax "amnesty", as all the tax and interest on it will still have to be paid in full.
It will not say how many people it thinks still have money hidden in the offshore accounts of the financial institutions it will target next year, although it clearly expects the figures to run into the tens of thousands.
"The effectiveness of the last campaign seems to have been a bit patchy," said Chas Roy-Chowdhury of the Association of Chartered Certified Accountants (ACCA).
"There must be some high-value targets the Revenue want to come clean," he added.
Last year the Revenue flushed out a list of 400,000 accounts it thought might be suspicious.
"Many of the customers for whom HMRC received information had already paid any tax due on funds invested and interest arising in the offshore accounts and had nothing to disclose," explained the Revenue spokesman.
Of the 100,000 or so people about whom it still had suspicions, 45,000 came forward and eventually paid £450m between them.
But about 50,000 others are still being investigated and some of these will soon be prosecuted.
"HMRC has made follow-up checks of the disclosures made and has started a programme of checks on those who did not take the opportunity to come forward," the Revenue spokesman said.
"In the most serious cases, we are carrying out criminal investigations and we will bring some prosecutions before the courts in the New Year," he added.
The Revenue will write to the latest tranche of banks and building societies, asking them to reveal the names and addresses of all its UK residents who have offshore accounts.
It will then write to them directly asking them to pay any unpaid tax.
Among the people who confessed last year were:
• someone who disclosed over £60,000 from a failure to declare rental income from a holiday home
• a woman worked all over the world and returned to the UK several years ago. She forgot about her offshore bank accounts where money was left after selling her last home overseas. Liability will be in the region of £44,000
• someone who sold a property portfolio, placed funds offshore and never declared them. Disclosure was about £1.7m
• a business man who diverted profits of about £1.3m into a Channel Islands bank account
• an employee with a disclosure of £200,000 to make, who placed a lump sum and dividends in a bank account offshore
• a businessman who diverted profits in excess of £800,000 into a number of offshore accounts
• a plumber who had paid about £10,000 from informal jobs into an offshore account
• a self-employed man who invested a £50,000 inheritance lump sum offshore.