More than a quarter of UK adults (26%) would invest up to £50,000 without professional financial advice, according to research by Mattioli Woods, despite 44% saying they do not feel prepared for major financial decisions ahead.
The gap is wider among men, with 34% saying they would be comfortable investing between £10,000 and £50,000 without advice, compared with 19% of women.
Some 30% of respondents said they would seek professional advice for all financial decisions while 21% would be comfortable making pension and retirement decisions without any professional input.
When facing an important financial decision, 41% said they would turn first to family or relatives, ahead of the 31% who would approach a professional financial adviser.
Those aged 55 and over were more likely to seek an adviser, while younger respondents favoured family support.
After family and advisers, respondents said they would most likely turn to a bank or building society, then to friends or colleagues.
One in 10 said they would make the decision alone.
Rising living and housing costs were the most commonly cited concern, at 40%, followed by unexpected health or long-term care costs at 39% and loss of income at 33%.
Respondents said long-term financial planning should begin at an average age of 28.5, rising to 30 among those in London and Wales.
Amit Joshi, managing director of wealth at Mattioli Woods, said the findings show that people recognise the need to plan for their financial future but do not always act on it.
"The concern, however, at seeking advice later on in life is the limited time to develop financial security, so we encourage individuals to start planning earlier with an adviser," he said.
He added that evolving tax, pension and inheritance rules make professional advice valuable when people are making long-term financial decisions with lasting consequences.
"It is understandable that people turn to family and friends when faced with an important financial decision," he said.
"However, decisions around investments, pensions and long-term financial planning can have unanticipated and significant consequences that last decades."
The findings are based on research carried out by YouGov among 2,078 UK adults, surveyed between 2 and 3 September 2026, on behalf of Mattioli Woods.