Today's agreement with the Swiss bank UBS that it will turn over details about 4,450 U.S. clients' accounts shows that the Internal Revenue Services is going to be "relentless" about going after Americans who it thinks are trying to evade taxes by parking assets overseas, IRS Commissioner Douglas Shulman just told All Things Considered co-host Robert Siegel.

If you've got one of those questionable overseas accounts and want to stay out of jail, Shulman says, fess up now. Here's some of what he had to say:

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Much more will be on ATC later today. Click here to find an NPR station near you.