The proportion of complaints upheld against the largest adviser firms fell sharply during the first six months of 2018, according to data from the Financial Ombudsman Service (Fos).
St James's Place and Openwork, two of the largest financial advice firms in the country, received 57 and 66 complaints respectively while Sesame, which closed its wealth division in 2015, received 103.
While Sesame saw its number of complaints go up from the last six months of 2017 - from 88 to 103 - the other two companies saw their complaint numbers go down.
But Sesame did see the number of complaints upheld fall dramatically, from 30 per cent in the previous six month period to 12 per cent in the first half of 2018.
Meanwhile, St James's Place saw its proportion of upheld complaints fall from 29 per cent to 15 per cent and Openwork saw this measure fall from 47 per cent to 23 per cent.
Last year Openwork saw its number of upheld complaints through the Fos spike, which the network attributed to a specific subset of complaints relating to a former adviser and reflecting advice given in 2010.
For providers, Aviva topped the list for pension complaints, with 291, and Barclays received the most investment complaints, with 476.
Meanwhile Bank of Scotland received the most mortgage complaints, with 773.
The biggest banks again topped the overall list for the number of complaints received, with Bank of Scotland receiving the most at 23,552 and Lloyds Bank coming second with 19,996.