Key takeaways
- The HMRC National Insurance helpline is 0300 200 3500 for Class 1, 2 and 3 queries, or +44 191 203 7010 from outside the UK.
- The line is open Monday to Friday, 8am to 6pm, and is closed on bank holidays.
- Class 4 National Insurance queries from the self-employed go to a separate number, 0300 200 3310.
- HMRC cannot give you your National Insurance number over the phone or on webchat; use the HMRC app or your personal tax account instead.
- You can usually pay voluntary contributions for gaps in the past 6 years, with a deadline of 5 April each year.
- Voluntary National Insurance for 2026 to 2027 costs £3.65 a week for Class 2 and £18.40 a week for Class 3.
- HMRC's average call answer time across all helplines was 8 minutes 20 seconds in August 2026.
The HMRC National Insurance helpline is 0300 200 3500, open Monday to Friday, 8am to 6pm, and closed on bank holidays. It deals with Class 1, 2 and 3 National Insurance, including gaps in your record, credits and statements. Self-employed people with a Class 4 query should call 0300 200 3310 instead.
Which National Insurance number should you call?
The number depends on the class of National Insurance and where you are calling from. These are the numbers on HMRC’s National Insurance: enquiries page, checked on 6 November 2026.
| Query | Number | Notes |
|---|---|---|
| Class 1, 2 and 3 | 0300 200 3500 | Main NI line |
| Class 4 (self-employed) | 0300 200 3310 | Profits-based NI |
| Textphone | 0300 200 3519 | Classes 1 to 3 |
| Relay UK | 18001 then 0300 200 3500 | Classes 1 to 3 |
| Outside the UK | +44 191 203 7010 | Same hours |
All lines open Monday to Friday, 8am to 6pm. HMRC last updated the page on 19 December 2025, when it added Christmas and New Year opening times. For every other HMRC line, see our HMRC telephone numbers list.
What the helpline covers
The National Insurance helpline handles questions about your personal contributions record. HMRC lists these topics:
- gaps in your National Insurance contributions
- National Insurance credits
- changes to your details
- rates of National Insurance
- Statutory Payments
- online statements of your record
Employers with a payroll query about employer NI should use the HMRC employer helpline on 0300 200 3200 instead.
What to have ready before you call
You need your National Insurance number, if you have one. HMRC also says your details in your personal tax account must be up to date, or you could fail telephone security.
Use this checklist before you dial:
- your National Insurance number
- the tax years your query is about
- any HMRC letter, with its date and reference
- your current address as HMRC holds it
- a pen, to note the adviser’s name and the date of the call
What you can do online instead
Many National Insurance tasks are quicker online, and some cannot be done by phone at all. HMRC says it cannot give you your National Insurance number over the phone or on webchat.
| Task | Where to do it |
|---|---|
| Find a lost NI number | HMRC app or personal tax account |
| Check your NI record | GOV.UK online service |
| State Pension forecast | GOV.UK online service |
| Pay voluntary NI | Online, through your record |
| Change name or address | Personal tax account |
The check your National Insurance record service shows contributions up to 6 April 2026, credits, and gaps that do not count as qualifying years for the State Pension. It also shows whether paying voluntary contributions would help and what it would cost. You can ask for a printed statement by phone, but not for the current or previous tax year.
HMRC’s digital assistant can also answer questions about contributions and pass you to an adviser if one is free. See our guide to HMRC webchat and the digital assistant.
Paying voluntary National Insurance to fill gaps
You can usually pay voluntary contributions for the past 6 years, and the deadline is 5 April each year. GOV.UK gives the example that you have until 5 April 2032 to fill a gap in 2025 to 2026.
| Class | 2026 to 2027 rate | Who usually pays |
|---|---|---|
| Class 2 | £3.65 a week | Self-employed with profits under £7,105 |
| Class 3 | £18.40 a week | Others with gaps |
For Class 2 in the previous tax year, and Class 3 in the previous 2 tax years, you pay the original rate for those years. Our guide to Class 2 National Insurance in 2026 explains when Class 2 is treated as paid.
Check your record and State Pension forecast before you pay, because a gap does not always reduce your pension.
Which applies to you?
- If you are self-employed with a Class 4 query, call 0300 200 3310.
- If you have lost your National Insurance number, use the HMRC app or personal tax account, not the phone.
- If you want to fill a gap in your record, check it online first, then call 0300 200 3500 if the service says you cannot pay online.
- If you live abroad, call +44 191 203 7010; our guide to contacting HMRC from abroad has the other lines.
- If you have reached State Pension age, GOV.UK points you to the Pension Service, or the International Pension Centre if you live abroad.
When is the line least busy?
HMRC does not publish waiting times for the National Insurance line alone. Its performance data, published on 8 October 2026, gives an average across all helplines.
| Month (2026) | Average wait | Calls over 10 minutes |
|---|---|---|
| June | 11:46 | 50.0% |
| July | 9:38 | 40.3% |
| August | 8:20 | 34.8% |
Our guide to the best time to call HMRC sets out the patterns by day and month.
Writing to HMRC about National Insurance
You can write to PT Operations North East England, HM Revenue and Customs, BX9 1AN. HMRC says you do not need a street name, city or PO box. Include your National Insurance number on every letter.
Frequently asked questions
What is the HMRC National Insurance helpline number?
The number is 0300 200 3500 for Class 1, 2 and 3 queries. From outside the UK, call +44 191 203 7010.
What are the National Insurance helpline opening hours?
The line is open Monday to Friday, 8am to 6pm. It is closed at weekends and on bank holidays.
Can HMRC tell me my National Insurance number over the phone?
No. HMRC says it cannot give your number by phone or webchat. Find it in the HMRC app, your personal tax account, or on a payslip or P60.
How far back can I pay voluntary National Insurance?
Usually for the past 6 years. The deadline is 5 April each year, so gaps in 2025 to 2026 can be filled until 5 April 2032.
What number do I call for Class 4 National Insurance?
Call 0300 200 3310. Class 4 is the profits-based National Insurance paid by the self-employed through Self Assessment.
Sources
Rates, thresholds and rules in this guide were checked against HMRC and GOV.UK guidance on 6 November 2026. Tax rules change, so check the current position on GOV.UK or with a qualified adviser before acting. This guide is general information, not personal advice.