If you've just arrived in the UK and want to work, one of the first things you'll need is a National Insurance (NI) number. It's how the government tracks your tax contributions and makes sure you're entitled to benefits like the state pension down the line.
The good news? Applying is free, straightforward, and entirely online. Here's exactly how to do it.
What is a National Insurance number?
Your NI number is a unique personal reference — it looks like AB 12 34 56 C (two letters, six digits, one letter). Think of it as your tax ID. Once you get one, it's yours for life — it never changes, even if you change your name or leave the UK and come back.
You need one to work legally and make sure you're paying the right amount of tax. Without it, you could end up on an emergency tax code, which means you'll pay more tax than you should.
Who needs to apply?
You need to apply for an NI number if you've moved to the UK and have the right to work here. That includes people with:
- A work visa (Skilled Worker, Graduate, etc.)
- A student visa with permission to work
- A Biometric Residence Permit (BRP)
- Settled or pre-settled status under the EU Settlement Scheme
If you were born in the UK, you'll usually be sent one automatically just before your 16th birthday. This guide is for people who've moved here from abroad.
Step-by-step: how to apply
Check you're eligible
You need the right to live and work in the UK. This means having a valid visa, BRP, or settled/pre-settled status. If you're not sure about your immigration status, check with your employer or a qualified adviser before applying.
Apply online via GOV.UK
Head to the official GOV.UK website and search for "apply for a National Insurance number." The online form takes about 20–30 minutes. You'll be asked about your right to work, personal details, current address, and employment situation.
Prove your identity (if asked)
In some cases, you'll be asked to verify your identity by uploading a photo of your passport or BRP through the GOV.UK identity verification service. Not everyone gets asked for this, but have your documents handy just in case.
Wait for your letter
After applying, your NI number will arrive by post within 2–4 weeks. It comes as a letter to the address you gave in the application. If it's been longer than 4 weeks, you can call the National Insurance helpline to chase it up.
Tell your employer
Once you've got your NI number, pass it on to your employer (or payroll team) so they can update their records. This makes sure you're being taxed correctly going forward.
Keep it safe
Your NI number is yours for life. Store it somewhere safe — you'll need it for tax returns, pension queries, and other official business. You don't need to carry the letter around with you day to day.
Can I start work before I get my NI number?
Yes — and this is a really common question. You don't need to wait for your NI number to start a job. Just tell your employer you've applied, and they can use "applied for" as a placeholder on their payroll system. Your tax records will be updated once your number comes through.
How long does the whole thing take?
The application itself takes about 20–30 minutes. After that, you're looking at 2–4 weeks for the letter to arrive. So in total, from start to finish, you should have your NI number within a month.
Track your NI number application
Use FormMate's interactive NI number checklist to track your progress step by step — so you know exactly where you are and what's next.
Start the NI number checklist