Integrafin, the parent company of platform Transact, will float on the London Stock Exchange via an Initial Public Offering (IPO) valuing the business at £649m.
Plans to float the company were first muted in January 2017, and followed an unsuccessful attempt to sell the business in 2014.
Integrafin was founded in 1999, and launched Transact in 2000 as an adviser-only platform.
The shares will begin trading on the market on 2 March.
The company fully owns its own technology and intellectual property, something that is relatively rare among platforms, with technology usually provided by a third party firm.
The float will see 27 per cent of the shares in the company sold to the market.
Peel Hunt acted as broker and bookrunner on the deal.
Ian Taylor, chief executive of Integrafin, said: "We have been delighted with the response IntegraFin has received from investors and welcome them to our business.
"It is 19 years since our foundation as the UK's first business to business (B2B) platform company and the support we have received to date is a strong reflection of our successful growth since inception."