Fusion Wealth, the platform backed by Schroders, has extended its relationship with SEI with a deal that will see the companies work together until at least 2025.
The two companies will be working on a series of projects to upgrade the platform but also to make sure it is able to handle the increased scale which might come from the advice joint venture being launched by Lloyds Banking Group and Schroders.
Lloyds and Schroders plan to launch the business by the middle of 2019, with Fusion Wealth providing its technology to the new venture.
Brett Williams, managing director of SEI Wealth Platform UK Private Banking, said: "The customer is the same customer but we are talking about scale here. It is partly about making sure we have got the scalability in the platform [for the Lloyds/Schroders joint venture]."
As well as scalability, Fusion Wealth and SEI will work on an "enhanced customer reporting suite" and "advanced and innovative digital services" as well as "next generation" retirement savings.
Ian Cook, chief executive of Fusion Wealth's parent company, Benchmark Capital, said: "We have got quite ambitious plans about what a pension portal needs to do.
"Over 50 per cent of assets we hold are in pensions and a lot of those customers are getting to the point where they need to draw income."
He said Fusion Wealth's plans would involve automating as much of the retirement advice process as possible so advisers could focus on more important parts of the process and clients would see the cost of advice fall.
Mr Cook said: "This is one of the most exciting things we are doing over the next 12 months."
Fusion Wealth and SEI have been working on the platform together since the former was launched in 2011.
In 2016 Schroders bought a stake in Benchmark Capital, which owns Fusion Wealth, advice firm Aspect8 and network Best Practice IFA Group.