AJ Bell saw a 5 per cent rise in assets under administration for the six months to 31 March as the company prepared to float on the stock market.
In its results statement, the platform business said it expected to commence its initial public offering (IPO) on the main market of the London Stock Exchange at the end of this year or early next year.
AJ Bell reported net platform inflows of £3.5bn in the six month period covered by the results, an increase of 17 per cent.
This translated into a rise in revenues of 16 per cent to £42.9m, and higher profits to the tune of 24 per cent, at £13.9m.
Andy Bell, chief executive of AJ Bell said: "These are the most profitable interim results in our history and are a great endorsement of our strategy and market position.
"Our brand heritage, platform technology and positioning across both advised and direct-to-consumer markets enables us to benefit from this long term growth story.
"Our propositions are designed to be easy to use, at a competitive price and we continue to focus on delivering a great customer experience, which is rewarded by the loyalty of our customers.
"We are well placed to continue our growth trajectory and are progressing well with our plans for a premium listing on the London Stock Exchange later this year or early 2019."
The asset growth was driven by growth in the platform assets, though the company also launched two new multi-asset funds for its managed portfolio service and a Lifetime Isa product it said has "proved popular".
The company said its total number of customers rose to 183,482, from the previous total of £164,557 at the end of September 2017.