By Mark Sanders
Europe business reporter, Liechtenstein
Stephen Timms (centre) said the deal would have been 'inconceivable' a year ago
The taxman cometh - and little Liechtenstein decided to put on a show of welcome.
Motorcycle outriders shepherded the British delegation through the streets of Vaduz, even though there's not much traffic in the small capital to delay dignitaries.
The convoy pulled up outside the main government building and out came the UK Treasury minister, Stephen Timms, and Dave Hartnett, head of tax at HM Revenue & Customs (HMRC).
"When I look back over the years, I never imagined I'd be here," Mr Hartnett said.
Shrouded in secrecy
Liechtenstein, the tiny principality in the Alps between Switzerland and Austria, has been renowned for the secrecy that shrouds the financial affairs of the wealthy who keep their money here.
But it has done a deal with the UK which it thinks can balance banking confidentiality with tax transparency.
After the signing ceremony Stephen Timms explained his surprise that such an event had taken place.
"A year ago, I think it would have been inconceivable," he said. "That changed with the G20 [summit] in April which created a completely new momentum behind agreements of this kind."
The economic and financial storm hit tax receipts and created a new climate for tax havens.
Governments around the world are eager to trace and recover revenue that should have been paid to them. And Liechtenstein is learning to adapt.
"What Liechtenstein has done is really look at the long-term wellbeing of its financial services industry, recognising that the game is up for tax evasion.
"It's putting in place, I think, a very impressive agreement that's to the advantage of the UK Exchequer but also to the advantage of Liechtenstein's banks," said Mr Timms.
Mr Timms hopes the agreement means that within five years no British account holders in Liechtenstein will have money hidden from HMRC.
Put simply, the main part of the deal is this: UK investors will be urged to come clean with tax officials back home about what assets they have squirreled away in Liechtenstein.
If they do, they'll be given more favourable terms to settle their tax affairs.
If they do not co-operate with HMRC, then Liechtenstein will close their accounts.
It is important to note that Liechtenstein will not be handing over bank details to the UK as part of this.
In effect it will ask investors who are not playing ball with HMRC to leave.
Such a system gives super-rich tax dodgers the possibility of moving their money out the principality and putting it elsewhere.
David Hartnett from HMRC gave an estimate of the kind of money he suspects Brits have squirreled away here: "We think the amount is somewhere in the region of £2-3 billion.
"It could be more, it's unlikely to be less. And we expect to recoup around £1bn back into UK coffers over time."
So what's in this deal for Liechtenstein?
Perhaps a sort of respectability when other off shore tax jurisdictions are squirming under international pressure.
Liechtenstein's ruling royal family is behind the agreement. Prince Nikolaus of Liechtenstein was at the signing ceremony to represent the family.
He suggested it was wrong to think that all account holders here were trying to shirk their tax obligations.
"Of course you will find all sorts of clients here," he told the BBC.
"You will find those who are totally clear with their tax situation. Then of course you will find some who have made all sorts of constructions to hide their money. Well, they now have a new situation."
But some in Liechtenstein's financial sector are far from happy with this deal, which goes further than the tax agreements the state has made with Germany and the United States.
"What we seek is a level playing field for all countries and that's why we oppose the agreement," said Clemens Laternser, deputy managing director of the Liechtenstein Trustees Association.
"It goes beyond the OECD standards [on tax transparency] and we don't see the point of it. Why should Liechtenstein give more than other countries are prepared to give?"