“We have now gained access to thousands of taxpayers and bank accounts that we have never had before,” IRS Commissioner Doug Shulman said at a press conference in Washington. “It has sent a shock wave around the world. It has shown we are serious about piercing the veil of bank secrecy. The whole game has changed."

Thousands of taxpayers came forward in the last days before the amnesty program expired on 15 October Mr Shulman said.

The total in taxes, interest and penalties collected from the voluntary disclosure program will be in the "billions of dollars," according to Mr. Shulman.

Also on Tuesday, the IRS and the Swiss government unveiled the criteria being used to determine which American UBS accounts will be disclosed under the August agreement.

Accounts being targeted include those that contained 1 million or more Swiss francs  (about $985,000) at any time between 2001 and 2008; instances in which there was clear fraudulent actions, such as false documents; and accounts that earned an average of SFr100,000 a year for at least three years.

The Swiss have until the end of August to hand over the names.

According to the IRS, UBS will also disclose accounts for which holders did not file a special disclosure document, called a W-9, over at least three years, and for which the accounts generated annual revenue to the client of at least SFr100,000 or about $98,500.

The number of voluntary disclosures would not affect the obligation of UBS, which must disclose 4,450 names, regardless of how many clients come forward independently, Mr Shulman said.  UBS had selected 500 names so far, IRS officials said.

The 14,7000 disclosures included not just UBS clients but clients from other banks as well, according to the IRS.

In a statement released Tuesday, UBS said it was “confident that it will comply in a timely manner with all of its obligations.”