The charity aims to combat loneliness among old people
More than one million older people say they often or always feel lonely, a report by Help the Aged suggests.
The charity found more than a third of older people in the UK, including half of women aged over 65, now lived alone.
Nearly half a million pensioners only leave their houses once a week and a further 300,000 are entirely housebound, the report says.
The charity wants more help for older people and said many only get to interact with delivery people.
The report blames a variety of factors for causing people to become isolated.
These include low incomes, a lack of local services, such a post offices, and the absence of opportunities to pursue hobbies.
Many older people interact only with their postman on a day-to-day basis
Paul Bates Help the Aged
Amongst its recommendations, the report says the government should ensure the state pension is at a level which allows older people to live comfortable and stable lives.
Improved design of public areas, better healthcare and more provision of bereavement support are all issues which need to be tackled, the report says.
Help the Aged spokesman Paul Bates said: "Many older people interact only with their postman on a day-to-day basis.
"It was a million people who responded to our survey to say that they are often or always lonely, and 1.5 million older people say they don't look forward to Christmas at all.
Closure of services
"And in previous research we've done, 48% of people said the television was their main form of company."
He added: "Loneliness may not seem a massive problem to many people, but if you are an older person who literally does not see a single, other human being for an entire week, you are more prone to depression, you are going to need higher levels of social care and the cost to the tax payer is pretty significant."
70-year-old Pat Higgs' experience of living alone
The charity has also called on ministers and local government to consider the impact on older people of the closure of services and the relocation of public transport.
The government should also ensure cultural opportunities are funded for older people as well as other age groups, it adds.
Quality of life
Mr Bates said: "We want to make sure older people can remain active in their communities, whether its through work, volunteering, taking part in classes to learn new activities or intergenerational programmes with children.
"We want to ensure incomes support quality of life, not just subsistence. Too many older people really are struggling with poverty and that can make such an enormous difference to quality of life."
The charity, which has launched its annual fundraising campaign '1 Is The Saddest Number', is aiming to provide 25,000 older people with a Christmas meal with friends at a local day centre during the festive period.
Mr Bates also urged people to take a few minutes to check on older neighbours, relatives or friends, saying that it could "make all the difference".
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