How to trace an employee’s national inurance (NI) number


If your new employee has no or an invalid NI number, you should obtain the correct number from HM Revenue & Customs (HMRC). This article tells you how you can trace an employee’s NI number.


If your employee has an NI number but cannot provide the details

If an employee cannot provide their NI number and you do not have any documentation, such as a P45, which shows their NI number, you need to contact HMRC. If you are sending form P46, HMRC automatically trace the number and send you Form CA6856 to confirm it. Otherwise, you need to complete Form CA6855, Employee’s National Insurance number trace, or send your own schedule with the information in the following order:

Employee’s title , Surname , First names , Address , Date of birth , Gender , Works or payroll number , Date employment started , Date employment ended, if applicable , Employer’s PAYE reference

Tip: Sage 50 Payroll contains a CA6855 РNational Insurance Number Trace report that you can print directly from the software and send to HMRC. The report is available in the Employee reports folder. The details of any employees with a temporary NI number in their  record are included.

Send this information to:

HM Revenue & Customs

National Insurance Contributions and Employer Office

NMTS NI number tracing


Benton Park View

Newcastle Upon Tyne

NE98 1ZZ

Or fax the information to 0845 915 5327.

Once HMRC have traced the NI number they will send you Form CA6856. Note the NI number, and pass Form CA6856 to the employee for future reference.

Tip: When setting up a new employee, if you don’t know the employee’s NI number, the software automatically generates a temporary NI number from the information you have already entered.

For further information about taking on a new employee that does not have a NI number, please refer to HMRC Helpbook Day-to-day payroll – E13 or visit Business Link – PAYE when taking on a new employee – first steps.

If your employee is entitled to an NI number but does not have one

If your employee does not have an NI number, they must contact the Department for Work and Pensions Contact Centre on 0845 600 0643. For more information about obtaining a NI number, please visit HMRC Applying for a National Insurance number –

For further advice or technical queries

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01603 516350

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