The average cost of a UK funeral has jumped to an all-time high of £4,417, raising fresh accusations of excessive price charging at a time when customers are at their most vulnerable.

The annual SunLife Cost of Dying report found that funeral costs rose £146 in 2019, and now stand at more than double the £1,920 it recorded when it first began collecting data in 2004.

The Competition and Markets Authority is investigating the market after it found that costs have been rising at about 6% a year for the past 14 years. The outcome of its investigation is expected this spring.

SunLife said the full cost of dying was approaching £10,000 once the cost of the wake, headstone and other send-off costs were added. The rate of increase had dropped in comparison with earlier years, although funeral director fees were up 3.5%, it said.

The report found marked regional variations. The average cost of funeral in London is £5,963, compared with £3,489 in Northern Ireland.

Fewer people than ever are opting for a full burial and the vast majority of Britons now choose cremation. Only 23% of funerals organised in 2019 were burials, down 4% on 2018.

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Low-cost direct cremations are increasingly popular but remain a small part of the market. In a direct cremation there is no funeral service and the body goes straight to be cremated, usually in a plain coffin and at a time suitable for the crematoriums.

SunLife found that 4% of funerals are now direct cremations, and their typical cost fell during the year by 5% to £1,626. Nor is it only those on low incomes who are drawn to this option. David Bowie is said to have been secretly cremated in 2016 without any of his family or friends present after telling them he did not want a funeral service.

One in four people said they were shocked by the costs of a funeral. One family told the researchers: “The ‘disbursements’ – vicar, embalming, booking the crematorium - were almost £1,000. I had no idea.”

Another said: “I have never been so upset as I was when I realised just how much it all was and that we just couldn’t afford it.” Eight out of 10 funeral directors said people spent more money than they need to, usually on flowers, the coffin and the catering.

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Some attempts to cut costs backfire. One funeral director told SunLife: “We had a family who bought a wicker coffin off eBay for a third of the price ... When it arrived the standard was not at all good, the deceased could be seen through it. It meant we had to line it.”

The researchers found that while more people are opting for “celebration of life” funerals rather than traditional religious services, the choice of music remains the same.

The most popular funeral song in 2019 was My Way by Frank Sinatra and the most popular hymn was Abide with Me, the same as the year before. When researchers asked families of the recently deceased which song they would like to have at their funeral, the most popular choice was Time To Say Goodbye by Andrea Bocelli and Sarah Brightman.