A National Insurance (NI) number is a unique 9-character reference in the format AB 12 34 56 C. You need it to work legally in the UK, pay the right amount of tax, build up your State Pension entitlement, and access certain benefits. You can start work without one but you must apply as soon as possible — your employer needs it for payroll.
Who can apply?
You can apply for an NI number if you have the right to work in the UK and you live in the UK. This includes people on Skilled Worker visas, Student visas (with work rights), family visas, and those with ILR or British citizenship. You must be aged 16 or over.
How to apply — step by step
- Step 1: Go to gov.uk/apply-national-insurance-number and click "Apply online"
- Step 2: Answer questions about your identity, nationality, and UK address
- Step 3: Upload a photo of your passport or BRP (or access your eVisa details)
- Step 4: Submit the form — you will receive a confirmation email
- Step 5: HMRC may invite you to a phone or video interview to verify your identity (not always required)
- Step 6: Your NI number arrives by letter to your UK address — usually within 4–8 weeks
💡 Tip
You can start work before your NI number arrives. Give your employer your name, date of birth, and address instead — they can run payroll without the NI number temporarily. Tell them you have applied.
What documents do you need?
- Valid passport (the one used for your UK visa)
- Your UK visa or eVisa details (right to work evidence)
- Your UK address (you must have a UK address to apply)
- Contact details (email and phone number)
How long does it take?
Most applicants receive their NI number by letter within 4–8 weeks of submitting the online form. If HMRC requires an identity interview, this adds 1–2 weeks. If you have not received it after 8 weeks, contact HMRC on 0300 200 3500.
What if I already have an NI number from a previous stay?
NI numbers are permanent and linked to you for life — even if you left the UK and returned years later. If you had an NI number before, do not apply for a new one. Contact HMRC to retrieve your existing number using your name, date of birth, and previous UK address.
Can my employer use a temporary number?
No. Employers cannot use a temporary NI number. However, they can run payroll using your personal details (name and date of birth) until your NI number arrives, then update it. There is no penalty for the employee during this period.
Apply for your National Insurance number on GOV.UK
Apply for NI Number →