HM Revenue and Customs (HMRC) has said that it is in the process of sending out penalties to those employers who have not yet returned their 2008/09 P11D(b) annual return of Class 1A National Insurance contributions.
The returns were due by 6 July 2009.
HMRC said that the penalty for late submissions is £100 per 50 employees for each month the return is outstanding, running from 7 November 2009 to 6 March 2010.
The penalties are on top of the ones issued in November for the four months between 7 July and 6 November 2009.
Employers who have yet to file their returns should send them without delay, HMRC added.
Employers who get a penalty notice that they believe is wrong should contact the helpline, the number for which is on the notice.