Businesses who file late tax returns will face an escalating penalty based on their size and the number of months the return isn't filed.
This is one of several changes in effect under the Revenue's new penalties system. It will apply to tax returns up to, and including, 2013/14.
The penalty will be £100 per 50 employees for each month or part of the month the return is outstanding from 20 May 2014 to 19 September 2014.
Also, as part of HMRC's transition to in-year RTI penalties for late and non-filing, it's changing its approach to penalties for late PAYE returns.
When a late return is received, HMRC will issue a revised updated penalty notice showing the correct amount of penalty due.
The ICAEW's Tax Faculty said the new system will affect 2012/13 and 2013/14 tax years to avoid confusion as the new interim penalty rules need chasing letters of their own.
As the faculty notes, for last few years HMRC has been issuing penalty notices earlier to avoid shocking employers with escalated PAYE penalties some months after a missed end of year deadline.