Former UBS banker Bradley Birkenfeld is ready to give prosecutors and the IRS more information about the Swiss bank’s secretive operations in an effort to further postpone his prison sentence.

Birkenfeld is scheduled to start his 40-month jail term on Jan. 8, but he is hoping to get leniency from federal authorities in exchange for further disclosures, according to The New York Times. Birkenfeld is in a position to know. He has admitted to helping billionaire real estate developer Igor Olenikoff evade $7.2 million in taxes by hiding his assets from the IRS and California tax authorities, and he was apparently involved in many other such deals.

He had expected to get a lighter sentence after helping federal authorities pressure UBS into eventually agreeing to release thousands of names of U.S.-based account holders. But so far, the feds have stood tough, apparently waiting for him to spill the beans on more of these transactions. Meanwhile, Birkenfeld may eventually earn a healthy 30 percent chunk of the proceeds that the IRS eventually collects, as per an amended whistleblower law that encourages more people to come forward and report tax evasion to the IRS with the prospect of cash rewards if the information checks out.

But the first priority seems to be winning a Get Out of Jail Free card.