Tax information is based on HMRC rules for the 2026/27 tax year. Tax rules can change — always verify current rates at GOV.UK. This is not tax advice. Consider consulting a qualified tax adviser for your personal situation.
Contents
Can’t find your National Insurance number? Here’s how to track it down quickly.
For the wider cluster covering NI rates, credits and employer-cost context, use the main National Insurance hub.
Read more: See our Take Home Pay guide for a complete overview of this topic.
What Your NI Number Looks Like
Format
Component
Example
Two letters
AB
Six numbers
12 34 56
One letter (A, B, C, or D)
C
Full format
AB 12 34 56 C
What It’s For
Purpose
Why Needed
Tax
HMRC tracks your earnings
National Insurance
Contributions recorded
Benefits
Claims processed
Pensions
State Pension record
Employment
Employer needs it
Where to Find It
Check These First
Document
Where to Look
Payslip
Usually shown
P60
End of year tax summary
P45
When you leave a job
Tax return
Previous submissions
HMRC letters
Various correspondence
Pension statements
From provider
Benefits letters
DWP correspondence
Less Obvious Places
Source
Details
Old NI card
If you still have it
Student loan
SLC correspondence
ISA paperwork
Provider may have
Mortgage application
Your records
Employment contract
Sometimes included
Find It Online
Personal Tax Account
Step
Action
1
Go to gov.uk/personal-tax-account
2
Sign in with Government Gateway
3
Your NI number is displayed
If You Don’t Have Government Gateway
Step
Action
1
Go to gov.uk/government-gateway
2
Create an account
3
Verify your identity
4
Access Personal Tax Account
HMRC App
Feature
Details
Download
HMRC app (iOS/Android)
Sign in
With Government Gateway
View
NI number shown in app
Phone HMRC
NI Helpline
Details
Information
Number
0300 200 3500
Hours
Mon-Fri 8am-6pm
What they need
Your name, address, date of birth
Security
May ask security questions
What to Expect
Step
Process
1
Automated options
2
Security verification
3
They confirm your NI number
4
May post confirmation letter
Get Written Confirmation
Requesting Confirmation
Method
How
Online
Through Personal Tax Account
Phone
Ask HMRC helpline
Post
Write to HMRC
No More NI Cards
Old System
New System
Plastic NI card issued
No cards since 2011
Many people kept them
Check if you have one
Now use
Letters, online account
If You Never Had One
Automatic Issue
When
How You Get One
Age 16 (UK resident)
Sent automatically
Register for NIC
Issued if not automatic
Apply for benefits
May be issued
Applying for NI Number
Requirement
Details
Who needs to apply
Non-UK nationals, those not issued automatically
How
Call NI application line
Number
0800 141 2075
Process
Interview and documents
Required Documents
Document
Purpose
Passport
Identity
BRP (if applicable)
Immigration status
Proof of address
Two items
Evidence of why needed
Job offer, etc.
Working Without NI Number
Can You Start Work?
Question
Answer
Can employer refuse you?
No — can start without it
Will you be paid?
Yes
Will you pay correct tax?
May be on emergency tax
What to do
Apply ASAP, employer corrects later
What to Tell Your Employer
Information
Provide
Say
“I’ve applied but don’t have it yet”
Give
Other ID (passport, etc.)
Timeline
Usually get number within weeks
When you get it
Provide immediately
Emergency Tax
What Happens
Details
Without NI
May be taxed at higher rate
When assigned
Employer updates HMRC
Overpaid tax
Automatically refunded
Timescale
Usually sorted within months
Common Questions
“Is my NI number on my birth certificate?”
Answer
Details
No
Not linked to birth certificate
Issued separately
At age 16 or on application
“Can I find it from my NHS number?”
Answer
Details
No
Different systems
NHS number
Separate identifier
NI number
Tax and benefits only
“Can someone else find it for me?”
Who
Can They Help?
Employer
Can’t look it up for you
HMRC
Only tell you directly
Family
Can’t access your records
“What if someone knows my NI number?”
Concern
Reality
Fraud risk
Some, but limited
They can’t
Access bank accounts
They could
Try to work under your number
If suspicious
Report to HMRC
Protect Your NI Number
Good Practice
Do
Don’t
Keep in safe place
Leave lying around
Memorise it
Share unnecessarily
Only give to employer, HMRC, legitimate requests
Give to random websites
Legitimate Requests
Organisation
May Need It
Employer
Yes
HMRC
Yes
DWP
Yes
Bank (only sometimes)
For specific purposes
Pension provider
Yes
Summary: Finding Your NI Number
Method
Speed
Check existing documents
Instant
HMRC app/online account
Instant if logged in
Call HMRC helpline
Same day
Request letter
Few days
Apply (if never had one)
Few weeks
Your NI number is permanent and stays with you for life. Once you find it, note it down somewhere secure so you don’t need to find it again.