An estimated 850,000 eligible households a year fail to claim Pension Credit, according to the Department for Work and Pensions (DWP).

In an effort to boost take up, letters will be sent to two thousand people who are above state retirement age and already receive housing benefit in ten local authorities across Great Britain asking them to apply for Pension Credit.

Experts said practical intervention from Government to improve the number of eligible households in receipt of the top-up – which also unlocks a host of other benefits once awarded – is “long overdue”.

Tom Selby, head of retirement policy at investment platform AJ Bell, said: “Pension Credit is an extremely valuable but chronically underclaimed benefit available to low-income households in the UK.

“This is tragic enough on its own given the financial strain many of these people will be facing, but made even worse because those who do not claim Pension Credit risk missing out on cost of living payments, as well as a string of other valuable benefits. The next two cost-of-living payments this year are worth a combined £600 – money which could be the difference between making ends meet and not for many people.

“If the trial is successful, the Government must work rapidly to expand it across the entire country. However, the Government could and should do more.”

An estimated 1.4 million retirees are eligible for Pension Credit, but around half are currently struggling in poverty unnecessarily when they could claim the benefit.

It’s worth up to £201 per week and an average of £3,500 a year, plus claiming Pension Credit also acts as a gateway for other perks such as the free TV licence, council tax help and cost of living payments from the Government.

To be eligible, you must earn under £220 a week or £320 a week for a couple. The benefit will top-up your income to £201 or £306.85 if you have a partner, while those with a disability or care responsibilities could get an extra £42 to £76 more each week.

Selby added: “The Government must keep striving to make sure people are clear about when they can claim, myths are dispelled, and the claim process is as simple as possible.”

Check the Government’s online pension credit calculator to see if you’re eligible.