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.


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

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

How to apply

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

You must explain in your letter that you’re applying for a National Insurance number for a looked after child and give your contact details.

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
  • the contact details of the social worker who has written the letter

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 or fax the letter and photocopies of any documents to:

PT Operations North East England
HM Revenue and Customs

Fax: 0191 213 1262

Make sure you send photocopies, as we’re not able to send these back to you.

There must be a separate letter for each application for a National Insurance Number.

We do not accept emails.

What happens next

HMRC will send a letter to the child confirming their National Insurance number.

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

How to contact us

If you would like an update on your application for a child who is being looked after by a local authority, contact the 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

Published 18 August 2014
Last updated 2 December 2020 + show all updates
  1. The 'how to apply' section has been updated to confirm that we do not accept emails.

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

  3. First published.