National Insurance Deferment (Multiple Jobs) Calculator 2026
Calculate if you've overpaid National Insurance across multiple jobs. Apply for deferment to avoid paying above the annual maximum. Claim back via self assessment.
NI Deferment Calculator
Frequently Asked Questions
Why do I pay too much NI with multiple jobs?
Each employer applies the Primary Threshold (£12,570) and Upper Earnings Limit (£50,270) independently. If each employer treats you as a separate employee, you may get multiple Primary Threshold deductions and miss the 2% rate savings above the UEL.
How do I claim back overpaid NI?
If you file a self assessment tax return, HMRC will calculate any overpayment and refund it. If you don't normally file self assessment, you can write to HMRC with your P60s from all employers.
What is NI deferment?
If you expect to overpay NI because of multiple jobs, you can apply in advance for deferment (form CA72A) so that one employer deducts NI at the reduced 2% rate from the start, avoiding the overpayment.
When should I apply for deferment?
Before the start of the tax year (April 6) for the year you expect to overpay. HMRC sends a certificate to the relevant employer.
Does deferment work automatically?
No — you must apply. If you don't, you'll overpay NI and need to claim a refund retrospectively.
Is overpaid NI automatically refunded?
Not automatically unless you file self assessment. HMRC may write to you, but it's your responsibility to claim.
Can I defer Class 2 NI if self-employed and employed?
Yes — if you're both employed and self-employed, NI deferment may apply to Class 2 as well. Use form CA72A.
What if I have more than two jobs?
The same principle applies. Each employer calculates NI on their wages independently. The more jobs you have, the more likely you are to overpay.
Is there a time limit to claim NI overpayments?
You can claim overpaid NI for up to 4 tax years after the end of the relevant tax year.
Can my employer help with NI overpayment?
Employers can only follow PAYE rules for each employee individually. They cannot take into account other employment. You must deal with overpayments directly with HMRC.
Does the same apply to two self-employment sources?
For self-employed, Class 4 NI is calculated on total self-employment profits across all businesses — there is no overpayment risk. Overpayment risk arises when you have both employment and self-employment income.
Do pension contributions reduce NI overpayment?
Salary sacrifice pension contributions reduce the earnings on which NI is calculated. This can reduce (but not eliminate) potential overpayments in multiple job situations.