Two important points to keep in mind:
1. It is temporary – The bank payroll tax will have effect from the time of the announcement on 9 December 2009 until 5 April 2010 for all discretionary and contractual bonus awards.
2. There are exemptions – There is an exception for contractual bonus entitlements where the payer has no discretion as to the amount of the bonus because of a contractual obligation existing at the time of the Chancellor’s announcement.
On the basis that most people will be prepared to wait (perhaps) then it seems to me that few cheques to HMRC will be written.