Mayor Boris Johnson says 174,000 men and women are missing out on an extra 35-pounds a week.
So as part of his "Know Your Rights" campaign, he's urging the capital's older residents - and their carers - to check they're getting all the payments they're entitled to.
The details now from Liz Wickham.
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Assema Kedir Habib spoke at the commemoration of her brother Hashim Kedir and his family.
A 95-year-old man has been arrested on suspicion of murder after a 61-year-old female carer died after she suffered head injuries.
The man told his pensioner victim his floor needed replacing and offered to carry out the work.