Guidance

Get a National Insurance number for a looked after child

How to get a National Insurance number for a child who is in the care of a local authority.

Who can apply

Children who are looked after by local authorities do not automatically get a National Insurance number.

If you’re a children’s social worker, you’ll need to write a letter to HMRC to apply for a National Insurance number on a child’s behalf.

You must write a separate letter for each child’s application for a National Insurance number.

How to apply

Write to HMRC after a child is 15 years and 9 months old using your local authority’s official letter-headed paper.

Explain in your letter that you’re applying for a National Insurance number for a looked after child and give your work phone number and postal address.

You must also include:

  • a statement that you’re a social worker applying for a National Insurance number for a looked after child
  • the child’s full name
  • any previous names the child has used
  • the child’s date of birth
  • the date the child went into care
  • the child’s current residential address

If possible, the letter should also include:

  • any previous addresses (such as their parent’s old address or the child’s last address before they were taken into care)
  • a photocopy of any of the following:
    • the child’s birth certificate
    • their care order
    • the ID page of the child’s passport

If the child is an unaccompanied minor and supported by the Home Office, you must include photocopies of either:

  • the child’s Home Office documents
  • both sides of a residence permit

Post the letter and photocopies of supporting documents to:

PT Operations North East England
HM Revenue and Customs
BX9 1AN

Do not send original documents, they will not be sent back to you.

After you’ve applied

HMRC will usually send a letter to the child confirming their National Insurance number within 7 weeks.

If we need more information, we’ll get in touch with the social worker using the contact details in their application letter.

If you need an update on an application you’ve sent, phone the HMRC Juvenile Team:

Telephone: 03000 555 716
Monday to Thursday: 8:30am to 5pm (closed bank holidays)
Friday: 8:30am to 4:30pm
Find out about call charges

Updates to this page

Published 18 August 2014
Last updated 2 January 2025 + show all updates
  1. Information on what happens after an application for a National Insurance number has been submitted has been updated.

  2. The 'how to apply' section has been updated to confirm that we do not accept emails.

  3. The address to write to for applications for a National Insurance number for a looked after child has been updated.

  4. First published.

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