How to Check If You’ve Overpaid National Insurance

National Insurance contributions (NICs) are a key part of the UK tax system, helping to fund the State Pension and other benefits. Most people pay them automatically through PAYE or Self Assessment. But mistakes happen, and you may find that you’ve overpaid – especially if you’ve had multiple jobs, changed employment status, or gone self-employed.

This guide explains how to check if you’ve overpaid National Insurance, what causes overpayments, and how to claim a refund from HMRC.

Are You Paying Too Much National Insurance?

You might have overpaid National Insurance if:

• You had more than one job and your employers didn’t coordinate your NIC thresholds

• You earned below the Lower Earnings Limit, but NICs were still deducted

• You became self-employed and employed in the same year and paid both Class 1 and Class 4 NICs beyond the annual limit

• You made voluntary contributions that weren’t needed

• You were over State Pension age but NICs were still deducted from your wages

• You left the UK part-way through the tax year

HMRC doesn’t always automatically issue refunds, so it’s important to check your record yourself.

How to Calculate or Check National Insurance Contributions

To review your contributions:

1. Log into your Personal Tax Account at www.gov.uk/personal-tax-account

2. Go to "Check your National Insurance record"

3. Review your contributions by year, including whether you’ve overpaid or underpaid

4. Use your payslips and P60s to cross-check the NICs deducted by your employer

5. If self-employed, check your Self Assessment summary for Class 2 and Class 4 NIC totals

Each tax year will show whether it counts as a qualifying year for your State Pension.

Examples of Overpayment

Example 1: Multiple Jobs

If you worked two part-time jobs and both paid you just under the NIC threshold, neither employer may have deducted NICs. But if combined, your income exceeded the threshold, you may have underpaid or overpaid depending on how it was handled.

Example 2: Self-Employed and Employed

If you are both employed and self-employed, you may pay both Class 1 and Class 4 NICs. If the combined amount exceeds the annual maximum, you can claim back the excess Class 4.

Example 3: State Pension Age

Once you reach State Pension age, you stop paying Class 1 and 2 NICs. If your employer continues to deduct NICs in error, you can reclaim it.

How to Claim a National Insurance Refund

If you’ve overpaid NICs, you can claim a refund from HMRC by:

• Filling in a CA5610 form (if you believe you’ve paid too much through PAYE or due to multiple jobs)

• Writing to HMRC with details of your income, NI number, and why you think you’ve overpaid

• Calling HMRC on 0300 200 3500 for further guidance

• If self-employed, raising the issue through your Self Assessment

You’ll need to provide:

• Your National Insurance number

• Evidence of earnings (P60s, payslips, Self Assessment statements)

• Details of employment and employers during the tax year

• Bank details for the refund

Refunds usually take 4 to 8 weeks to process once HMRC receives your claim.

Voluntary Contributions and Refunds

If you’ve paid voluntary Class 2 contributions (for example, to top up your pension record) but later find out they weren’t needed, you may be eligible for a refund. This could happen if you had other qualifying income or already had enough qualifying years.

To check and request a refund, contact HMRC’s National Insurance team directly.

Final Thoughts

Overpaying National Insurance is more common than people realise, especially if you’ve had complex working arrangements or earned close to the thresholds. By checking your NIC record online and reviewing your annual earnings, you can spot overpayments and take action to reclaim what you're owed.

If you’re unsure, don’t hesitate to speak with a tax adviser or call HMRC directly – it’s your money, and you may be entitled to have it back.