Quilter has set aside £12m for potential defined benefit claims made against the recently-acquired Lighthouse by British Steel Pension Scheme members.
Quilter bought national advice company and network Lighthouse in a deal worth £46.2m, which saw an additional 390 advisers join the company's advice arm.
But since the acquisition the advice giant has been made aware of at least 30 complaints concerning advice given by Lighthouse to British Steel members in relation to transferring out of their defined benefit pension.
In the company's most recent financial results, published to the market this morning (March 11), Quilter confirmed Lighthouse had advised about 300 British Steel workers to transfer and roughly 80 took place prior to June 2017, after which the transfer values of the pension scheme were "fundamentally enhanced".
Paul Feeney, chief executive at Quilter, said: "Since the year-end we have been notified of around 30 complaints relating to advice provided by Lighthouse, all of which related to the pre-June 2017 period.
"We are in the process of reviewing those complaints and have written directly to the customers involved.
"Whilst Lighthouse has professional indemnity insurance cover in place, we have taken a provision of £12m on a gross basis to cover potential costs and this has been reflected as an adjustment to the acquisition balance sheet of Lighthouse."
Mr Feeney said Quilter had begun a review of all cases advised by Lighthouse prior to its acquisition in June 2019 and was "actively engaging" with the Financial Conduct Authority.
He added: "While this situation is obviously disappointing, our priority is to do the right thing for our customers."
Meanwhile the Quilter boss has set his sights on some of the Lighthouse advisers to become restricted and "fully integrated" with the advice giant this year.
In today's results Mr Feeney said over time he expects a number of the 250 independent advisers at Lighthouse to convert to a restricted proposition.
Speaking with FTAdviser, Mr Feeney said he would like to see this transition completed in the coming year.
He said: "As the chief executive I would like to have Lighthouse fully integrated this year.
"We purchased Lighthouse a bit later than Charles Derby, and the latter is now virtually 100 per cent integrated.
"And I'd like to see fully Lighthouse integrated and whoever is coming over is over this year."
The Quilter boss said requiring advisers to become restricted was a "trend in previous acquisitions" and would be based on the ability of the company's products to meet customer needs.
Another of Quilter's significant acquisitions last year was the purchase of Charles Derby in February, in a deal which added 200 financial planners to the business.
But Mr Feeney said the company's acquisition pipeline was "not a top priority" for 2020, with Quilter instead looking to focus on integrating the deals made last year.
The advice giant swung into a loss last year with a statutory pre-tax loss of £53m, down from a profit of £41m in 2018, which its chief executive attributed to costs associated with Quilter's acquisitions, platform transformation and restructuring costs.