Single people pay proportionately more than couples for everything from tax to gym membership to homes.
Now a rebellion is growing against an irksome feature of life for Britain's growing band of singletons, the holiday single supplement.
The country's largest consumer organisation, Which?, has called for an end to the practice of charging lone holidaymakers more for a room than a couple, saying it can no longer be justified. Researchers found that single supplements can amount to the entire price paid by a couple for occupying the same accommodation.
"While other service industries such as retailing have made strides to cater for singles, for example supermarkets providing a range of individual meals, the holiday industry penalises solo travellers," Holiday Which? complained. In an appeal to the travel industry, it said that lone travellers should have to pay no more than 50 per cent of the cost for two people on the same holiday.
The demand will resonate with the rising number of Britons outside relationships, divorced or living on their own. Figures from the Office of National Statistics show that the number of people living alone has almost trebled during the past 30 years to 10 million. By 2010, the ONS forecasts the single population to hit 16 million.
But single people are not the only ones who like to explore the world on their own, research by Mintel makes clear. Fifty-three per cent of people sometimes like to go on holiday on their own, and two-thirds said going on holiday alone was a good way to meet people.
Some mainstream travel companies are now recognising that single people can be a lucrative source of business. Lastminute.com, for instance, offers single holidays with low or no single supplement and says the market for lone travel is "fast-growing".
Niche operators are also catering for the increasing number of lone travellers. The companions2-travel.co.uk and someone2travelwith.com websites allow lone travellers to search for a compatible member to go on holiday with.
More conventionally, tour operators such as Friendship Travel organise trips for singletons where they will not stand out for being on their own. Solo's Holidays, for instance, runs escorted trips worldwide, such as seven days exploring Croatia's rugged coastline, or a week-long safari in Kenya. Unlike many tour operators, the operator based in Edgware, north-west London, actively discourages people in relationships from joining its trips. They are aimed at establishing friendship between singletons who, within one or two days of arriving, go out together as a group in the evening.
The managing director, Gill Harvey, wished to dispel the image of a sad holidaymaker dining alone at night, while all around couple and families had fun. "The sheer fact that these people are getting up and doing something and going on holiday shows they have get-up-and-go, and are sociable. It's the people who are stay-at-home and don't want to do anything about who may be less gregarious," she said. Most of Solo's clients are in their thirties and upwards.
Which? advised anyone thinking of going on holiday on their own for the first time to visit a museum, restaurant or cinema solo before booking. "If you want interaction with others, even if it's just a hello at breakfast, choose a small B&B, guesthouse or hotel where you know you'll get the personal touch. If you want anonymity, go for a larger hotel."
In a poll, 38 per cent of Which? members had spent at least one night in a hotel, B&B, or a cruise alone. Only one in 10 thought their treatment as a single traveller had been worse than when they had been with other people, but one quarter thought they had been given a raw deal at dinner. Almost half objected to the price they had paid. More than two thirds thought that it was unfair of hotels or holiday companies to charge a single supplement.