With hard-pressed employers coming to terms with Real Time Information (RTI) filing, the pain is not all over.
There can be penalties.
Penalties can be applied for inaccurate in-year 2013-14 returns so do try to be as accurate as possible with employee data. HMRC have however stated that they will use a risk-based approach for identifying employers who may be submitting inaccurate returns.
For late in-year returns during 2013-14 there is a concession of no penalties, but to avoid a late filing penalty for 2013-14 final returns must be submitted before 19th May 2014. Also note that RTI does not change the obligation of Employers to pay deductions over to HMRC fully and on time.