More than 14,700 Americans hoarding untaxed cash in offshore banks have agreed to disclose and split billions of their secret booty with Uncle Sam to stay out of jail.

Most of the tax cheats, or about 12,000, stampeded en masse out of hiding behind secret Swiss bank accounts just days after the US won a long legal fight to pierce a centuries-old practice of secret banking in Switzerland.

Internal Revenue Service Commissioner Doug Shulman said tax cheats rushed forth for a fresh Start after the IRS got Swiss bank UBS and its government to turn over records on 4,450 accounts.