HMRC have recently introduced “KC” as a new prefix for National Insurance numbers. This change was not included in the specification HMRC provided to payroll software developers this year. It’s also not catered for by the Government Gateway itself. As a result, Opera 3, Opera II and Capital Gold payroll systems do not accept NI numbers with the KC prefix, and FPS submissions containing these NI numbers are currently being rejected.

Until this issue is resolved, HMRC guidance to employers is not to enter NI numbers with the KC prefix into their payroll systems. We therefore advise users of Opera 3, Opera II and Capital Gold Payroll to leave the National Insurance Number field blank when adding a new employee with a KC NI number, and ensure that the employee’s name and address details are completed in full as HMRC will be using these as employee identifiers.