Verifying Employee National Insurance Numbers

Introduction

As an employer, you need to verify that employees' National Insurance numbers are correct before processing their payroll. HMRC provides a free online service called Basic PAYE Tools that allows you to check whether an employee's National Insurance number is valid and matches their personal details.

What is a National Insurance number verification request?

A National Insurance number (often shortened to NI number or NINO) is a unique reference used to track an individual's National Insurance contributions and tax records. When someone starts working for you, they should provide their National Insurance number, but you need to verify it's correct to ensure your payroll records are accurate and HMRC receives the right information.

The verification process confirms that the National Insurance number exists and matches the employee's name and date of birth on HMRC's records.

Why you should verify National Insurance numbers

Checking your employees' National Insurance numbers helps you avoid problems with:

• Payroll submissions to HMRC – incorrect numbers can cause your Full Payment Submission (FPS) returns to be rejected or flagged with errors
• Employee tax records – wrong numbers mean tax and National Insurance contributions may not be credited to the correct person
• End of year returns – errors in National Insurance numbers can lead to delays and additional administrative work

Verifying the number at the start of employment saves time and prevents complications later in the tax year.

Before you can use Basic PAYE Tools

You must register with HMRC for PAYE Online before you can use Basic PAYE Tools. This applies whether you're using the tools to run payroll calculations, submit returns to HMRC, or simply verify National Insurance numbers.

PAYE Online registration gives you access to HMRC's digital services for employers and is required for anyone operating PAYE as an employer.

How to verify a National Insurance number using Basic PAYE Tools

Basic PAYE Tools is free software provided by HMRC that helps small employers manage their payroll responsibilities. One of its functions is to check employee National Insurance numbers.

To verify a National Insurance number:

1. Download and install Basic PAYE Tools from the HMRC website if you haven't already

2. Open the software and ensure you're logged in with your PAYE Online credentials

3. Navigate to the verification function within the tools

4. Enter the employee's details including their National Insurance number, full name, and date of birth

5. Submit the verification request to HMRC

6. Receive confirmation that the number is valid and matches the details provided, or notification if there's a discrepancy

The verification process checks HMRC's database in real-time, so you receive immediate feedback on whether the National Insurance number is correct.

What to do if an employee doesn't know their National Insurance number

If a new employee cannot provide their National Insurance number, you can also use Basic PAYE Tools to help find it. The employee will need to provide their full name and date of birth, and you can submit a request through the software.

However, employees can also find their National Insurance number on:

• Previous payslips
• P60 end of year certificates
• Letters from HMRC
• The HMRC app or their Personal Tax Account online

If the employee has never had a National Insurance number (for example, if they're a young person starting their first job), they should contact HMRC directly to apply for one.

Keeping Basic PAYE Tools up to date

HMRC updates Basic PAYE Tools when there are major changes to payroll rules or submission requirements. While the software isn't necessarily updated every tax year, you should check periodically that you're using the current version to ensure compatibility with HMRC systems.

The verification function remains available throughout the tax year, including during 2025/26, and you can submit verification requests whenever you take on new employees.

Record keeping

Once you've verified an employee's National Insurance number, keep a record of the confirmation in your payroll files. This helps demonstrate that you've taken reasonable steps to ensure the accuracy of your payroll records if HMRC ever queries your submissions.

You should also update your payroll software (whether that's Basic PAYE Tools or a commercial package) with the verified details to ensure all future payroll submissions use the correct information.

Getting help

If you experience technical difficulties with Basic PAYE Tools or have questions about the verification process, HMRC's employer helpline can provide assistance. The Basic PAYE Tools software also includes built-in guidance to help you navigate its functions.

For complex payroll situations or if you're unsure about your responsibilities as an employer, professional advice from an accountant can help ensure you remain compliant with PAYE regulations.

Sources

• Find or check an employee's National Insurance number using Basic PAYE Tools
• PAYE Online

This article provides general guidance based on current HMRC rules. For advice specific to your situation, speak to your accountant.