A fifth of grandparents get turned down for the £275 a year in benefits they can claim for looking after grandchildren - here's how to make sure you get yours.
The charity Age UK has found that one in five people over the age of 50 regularly care for their grandchildren.
That amounts to 5million people, but HM Revenue & Customs said fewer than 16,000 of them have joined a scheme that increases their pensions, the Mail reports.
The benefit is called Specified Adult Childcare Credits, which grandparents get when parents sign over their National Insurance (NI) contributions to their elderly relatives for looking after grandkids.
The state pension you get in retirement depends on how many NI credits you’ve built up over your working life.

You need at least ten years' worth of NI contributions to qualify for any sort of state pension, and at least 35 years to get the full amount, which is currently £185.15 a week.
If an elderly relative doesn’t get the full amount, and spends a lot of time looking after grandchildren under the age of 12, it is possible to top up their state pension by allowing them to claim.
The current level of these benefits is £5.29 a week, which adds up to £275 a year.
While grandparents are most likely to benefit from the scheme, other family members can also claim.
These include uncles, aunts, siblings, cousins, non-resident parents and partners of any of these relatives.
Last year The Mirror found there had been almost 78,000 applications for the credits over the previous five years, but 16,000 were rejected.
Around 15,580 people apply for the benefit every year, with only 12,385 of those being successful.
The benefit is severely underclaimed. In 2018 government said 100,000 could claim the credits, but at the time only 19,000 had done.
How to apply for Specified Adult Childcare Credits
You can get these by using form CA9176 on the Gov.uk website.
Both you and the parent transferring the credit will need to sign the form, so you must be in agreement that you're happy to go ahead with the transfer.
You should also be aware that only one grandparent or family member can receive the credit - and the credit is per child benefit claimant, not per child.
You also must have been under the state pension age of 66 when you cared for the child in question.
The government will not take applications for any tax year until at least the following October.
Finally, the credits can be backdated to April 6, 2011, which is when the scheme came into effect.