Real Time Information (RTI) late filing
The Full Payment Submission (FPS) report under RTI should be submitted on or before the date the employees are paid. A concession which allowed employers with fewer than ten employees to submit one FPS per month, even if there were more pay days, ended on 5 April 2016.
HMRC is currently risk-assessing the issue of every RTI late filing penalty. This means that only employers who persistently file their FPS report late will be issued with a penalty - which can be appealed.
Also, any filing of the FPS within three days after the due date isn't given a penalty. This three-day grace period has been extended to all FPS reports due before 6 April 2017.
However, HMRC will monitor employers who regularly file late, even within three days of the due date, and they may issue those employers with a penalty warning letter. Note that the three-day grace period doesn't give the employer any legal protection as it is an HMRC concession - it is not written into law.