Are you a grandparent in the UK looking after a child? You could be eligible for NI credits

Guidance
Specified Adult Childcare credits: fact sheet

Overview
These National Insurance (NI) credits were introduced from April 2011. You may be entitled to receive these NI credits if you are a grandparent, or other family member, who cares for a child under 12, usually whilst their parent (or main carer) is working. These credits are only available from April 2011 and you must make an application to receive the NI credits.

What you’ll get
Specified Adult Childcare credits will help build up your National Insurance contributions. This means:

you will receive a Class 3 NI credit for each week or part week you cared for the child (Class 3 NI credits help to build entitlement to the State Pension and, until April 2017, certain bereavement benefits)
it can help to stop gaps in your National Insurance record

More info:
https://www.gov.uk/government/publications/national-insurance-credits-for-adults-who-care-for-a-child-under-12-fact-sheet/specified-adult-childcare-credits-fact-sheet