ERROR: This National Insurance number has been used for another active worker...

Solution Properties

Solution ID:

260109113144237

Last Modified Date:

Fri Jan 09 12:27:14 UTC 2026

Taxonomy Path:

Case category//I have a problem with...//processing

Author:

[email protected]

ERROR: This National Insurance number has been used for another active worker...

Description

If you get an error when you submit your pension contributions to Nest Pensions, use the steps below to help fix the issue.

Things to consider:

The terminology used is Nest terminology, not Sages
Nest generates the errors at the time of the transmission
Where possible, we list detailed steps to explain the cause of each error, and how to resolve them
Depending on the nature of the error, we can advise you to contact Sage support directly
For further information on the terms used, read Nest pension submission glossary

Cause

Resolution

Before you start

We recommend having your Nest login details to hand.

NOTE: When comparing details between payroll and Nest Pensions, they must be identical. This includes capital letters, lower case letters, special characters, leading or trailing spaces.

To find the full error message:

Select Summary from the menu bar.
From the Auto Enrolment/Pensions section, select View Submission Errors.

The error

The National Insurance (NI) number for a new employee matches the one that Nest already has in use.

There are a few possibilities:

Cause	Solution
The correct NI number in question links to the correct employee on both NEST and Sage Payroll. The employee could be a returning member of staff.	This suggests that the employee has already enrolled on the Nest website. If the Sage Payroll system is trying to enrol this employee: Upload the values of this pay period yourself via the Nest portal Mark it as complete within Sage Payroll The error won’t occur for this employee again.
The correct employee NI number is in Payroll but not on the Nest website.	Contact Nest to find the best way of correcting their incorrect NI number. Once changed you’ll be able to upload the pension contributions as normal.
The correct NI number is on the Nest website but not in Sage Payroll.	Correct the NI number in Sage Payroll. Open the employee record in question and correcting the Personal Details. Correct the NI number in Sage Payroll within the employee record. If you’ve processed a pay run for this employee using the incorrect NI number, contact HMRC to let them know of the issue.

Steps to duplicate