Jersey has signed a tax information exchange agreement (TIEA) with the UK.
As the Guardian says (with edits):
Terry Le Sueur, chief minister of the Channel islands tax haven of Jersey, is due in London today to sign a novel agreement which will share information about offshore tax dodging.
Treasury sources said yesterday the deal with Jersey had been "a long time coming", but was a result of the changed international climate.
The UK has been trying to persuade it to sign a deal for more than four years.
In 2007, members of the island's regime complained publicly they might lose business as a result, particularly to Switzerland, where tax evasion by foreigners has not been regarded as a crime.
Quite so. Jersey has resisted this for as long as it has been possible for it to do so.
Don’t expect them to cooperate with the UK now we have it. Jersey’s agreement with the USA has been used four times since 2001. Cayman, with its stronger ties with the USA has budgeted to deal with just 120 enquiries in the current financial year.
This is not cooperation: this is political gesturing. I hate to say it, but TIEAs are hardly worth the paper they are written on.