As practitioners will be aware, the 2008-09 Employer Annual Returns (P35 and P14s) were due by 19 May 2009. HMRC have advised that from 23 January they started to send penalty notices to employers from whom returns have not yet been received.
The penalty will be £100 per 50 employees for each month the return is outstanding, from 20 September 2009 to 19 January 2010. So, an employer with 50 or less employees will receive a £400 penalty. This penalty is in addition to penalties sent in September 2009.
Further details are available here.