The Taxman is causing RTI pains for employers and employees by issuing duff data.
Incorrect NI numbers
When you submit a FPS or NI number verification request (NVR), the Taxman should reply with any missing or corrected NI numbers. However, in some cases the NI numbers the Taxman has returned to employers have no suffix letter (A, B, C or D).
The Taxman says you should use the NI number he has sent to you in your payroll software, but to leave the last digit blank by typing a space using the space bar. This may not be a workable solution, because most payroll software will reject any NI number with less than nine characters. We're hoping for an HMRC update on this issue!
Sometimes a long standing NI number has been replaced, but the old NI number is quoted on official notices. This indicates a possible data corruption problem within the HMRC machine. You should exercise caution when amending any NI numbers notified by HMRC since 6 April 2013, and talk to us if in doubt.
Incorrect PAYE codes
Where you have submitted an FPS or employer alignment submission (EAS), which did not include all the employees normally on your payroll, without indicating that the EAS was a part submission, the Taxman has assumed that any missing employees have left your employment.
Subsequently when you submit a FPS including one of those missing employees, that employee is treated as a new starter, with a new employment record. Any details of benefits in the PAYE code belonging to that employee haven't been carried over to his new employment record. Thus his new PAYE code may be wrong.
The Taxman has advised employers in this position to use the old PAYE code for the employee. However, under the PAYE regulations employers are not permitted to take a view on which PAYE codes to apply and which to ignore. Many payroll software packages download the PAYE codes directly from HMRC and apply them automatically, with no human intervention.
The employer helpline will not discuss employee's tax codes with an employer, so the only way to straighten out the mess is to get the employee to contact the Taxman directly.