Grandparents providing childcare aren't usually eligible for any financial support. However, the government has introduced a National Insurance credit to ensure that grandparents and other relatives of working age who are providing childcare do not lose out on their basic state pension. The credits, called Specified Adult Childcare Credits are for anyone who is providing care for a young relative under the age of 12 in order to enable a parent to work.  You can get more information and an application form from gov.uk  or phone the National Insurance Helpline on 0300 200 3500.

Where a relative is providing childcare, parents cannot usually claim the childcare element of Tax Credits or Universal Credit or other help with childcare costs. The only exception is where the relative is a registered childminder and is looking after a child away from the child's home. Childminders have to register with Ofsted, advertise their services publicly and take on other (unrelated) children.