Almost 70 per cent of UK high net worth individuals make money from employment, investment income or through selling their businesses, according to the Skandia Millionaire Monitor Report, drawn from a survey of more than 500 millionaires.

Old money is less significant, with only 14 per cent of those surveyed saying their wealth comes solely from inheritance income. Trusting luck to make a fortune also appears to be a risky strategy, with just 4 per cent of the sample saying their wealth has come from winning the lottery or by gambling.

However, almost 15 per cent of wealthy younger people acquired their fortune through either winning it or through marriage – a three times higher incidence than those aged over 50 years of age.

The findings help explain why wealth managers are increasingly focusing, through their client segmentation and branding, on pitching to entrepreneurs and younger people. The recent Merrill Lynch Capgemini World Wealth Report 2011 found that on average, HNW individuals are getting slightly younger, driven by the economic advances in regions such as Asia-Pacific.

And in an implicit warning to policymakers looking to attract inward investment, Skandia’s report found that more than half of UK millionaires are or could consider leaving the country to find a higher standard of living.

Only 44 per cent are certain of remaining in the UK, while around 8 per cent are already planning to leave, the report said.

Taxation, perceived better living standards outside the UK and the weather contribute two-thirds of the rationale as to why UK millionaires would consider a move abroad. Despite this, under 2 per cent of those considering a move abroad are thinking of a move to a jurisdiction such as Switzerland or the Cayman Islands to reduce taxes.