Tax officials say they have received £250m in the last few days from people who were involved in tax avoidance schemes.
The biggest of these recent payments was for £5m.
HM Revenue and Customs has new powers to demand that users of tax avoidance schemes pay disputed tax up-front while their tax affairs are investigated, instead of waiting for a decision.
It does not name particular avoidance schemes behind the rush but sports figures, celebrities and other wealthy investors have been reported as facing demands for tax.
By sending out Accelerated Payments Notices, officials say they have "seized" £2bn since 2014, with half of that pouring in since September.
3,000 Notices a month are being issued, with a view to bringing forward over £5 billion tax revenue by March 2020.