The Financial Services Authority (FSA) has revealed that the number of advisers practising in the summer of last year was down 11.5% on the previous year, a fall of more than one in ten.
There are currently 35,899 retail investment advisers operating in the UK, according to the FSA's findings.
IFAs make up the largest group with 53% of the population, followed by advisers in banks and building societies at 19%.
The findings came from research carried out by the FSA late last summer in which it questioned 1,436 advisers.
It found that 89% of all retail investment advisers were definitely or likely to remain in their posts, with 6% - about 2,000 individuals - expecting to leave the industry or take on a non-advisory role.
Further research by the FSA in November and December found that 93% of retail investment advisers held an "appropriate qualification" - at QCF level 4 or above -, 2% were awaiting results and 2% were still studying.
About 3% of advisers did not intend to qualify to the required level.
Of advisers without an appropriate qualification, 2% aimed to hold one by the Retail Distribution Review (RDR) deadline of 31 December, with 2% intending to hold one after the deadline.
About 500 intending to qualify after 31 December were required to meet the RDR deadline and will need to stop advising, the FSA said.
'Right thing to do'
£69m spent on upgrades
European fintech market 'underserved'