Platforms saw the rate of assets under administration (AUA) growth jump by almost a fifth in the third quarter of 2014, according to research from Fundscape.
Total platform assets rose £9.7bn to £326.4bn - a rise of 3.2% on the previous quarter but 19.3% on Q3 2013.
However, while net sales were higher than at the same time in 2013, they were also down 15% on the previous quarter.
The new ISA allowance resulted in a strong uptick in ISA flows.
Direct to consumer giant Hargreaves Lansdown was the most popular platform, according to Fundscape estimates, with net sales of £1.5bn. Cofunds and Fidelity were second and third for net sales, respectively.
Fundscape chief executive Bella Caridade-Ferreira said: "The third quarter is traditionally the quietest of the year, mainly because of the summer holiday season. The new ISA allowance resulted in a strong uptick in ISA flows, but flows were subdued elsewhere."
In the wake of the government Budget reforms, which increased the ISA allowance, net ISA sales were up more than a third year to date, compared to the same period last year. Overall, ISAs accounted for 27% of net sales in the third quarter.
Flows to the corporate, institutional and D2C channels dropped back over the period, according to the firm. However, retail advice accounted for more than half of net flows.
In total, 59.5% of assets under administration were retail advised at the end of the third quarter, while 18.9% were corporate or institutional and 21.5% were D2C.
