Aegon, Aviva, AJ Bell and Transact are among the platforms charging an additional fee to so-called orphaned clients after their adviser has terminated their relationship.
The platforms defended the charges, saying they were needed to cover regulatory costs and extra administrative work.
Orphaned clients are those who have accounts on adviser platforms, but no longer have a relationship with the adviser who placed them on the platform.
FTAdviser asked some of the largest platforms - Aegon, Aviva, Standard Life, Quilter, Ascentric, Seven Investment Management, Fundsnetwork, AJ Bell and Transact - about their approach to such clients.
Of those firms, Aegon, Aviva, Transact and AJ Bell said they levy an extra charge, while Ascentric keeps the cost at the same level as for advised clients despite restricting the service available to orphaned ones.
An Ascentric spokesman said: "We restrict orphans to 'sell only'. This is because our platform is for advisers and has more complex investments on it, so we are protecting the client by not allowing them to buy new investments. They are able to sell to get their money off the platform. We do not let orphans go into drawdown, as this should be an advice event."
An AJ Bell spokesman said the platform charges an extra £50 a quarter to cover the additional administrative costs of there being no adviser and that it actively encourages clients to find a new adviser or move to a different platform.
Meanwhile, orphaned clients on Transact incur a 3 per cent charge on new investments while advised clients pay 0.05 per cent, and charges are 1 per cent a year for investments or pension pots worth up to £60,000, but 0.5 per cent for those who use an adviser.
A spokesman said: "This increase is charged to cover the additional servicing required from us. Adviser platforms tend to be cheaper than D2C platforms as advisers do lots of the work."
Aviva stated: "Charges vary depending on the individual circumstances of the client and their investments, but generally the platform charge is higher for DIY clients – this is because the DIY platform has to meet regulatory costs and overheads that are borne by advisers for advised clients. As these clients do not pay advice charges their overall cost is typically lower."
Meanwhile, Aegon stated: "As an intermediated platform that expects customers to have an active adviser we believe that it is appropriate for the platform to levy a charge for the additional administrative services that it has to take on board should the customer choose not to have an adviser."
A representative of Aegon said the policy was "under review" following the Financial Conduct Authority's interim platform market study published in July, which found some 10,000 orphaned clients were paying extra fees amounting to more than £1.2m every year.
"Following the platform market study we’re currently reviewing this approach to ensure it remains appropriate," they added.
The FCA has previously said it is considering measures to tackle price discrimination on platforms between orphan and existing clients.
In its interim study regulator said: "We have two main concerns. Orphan clients have limited ability to access and alter their investments on an adviser platform so are paying for functionality that they cannot use.
"While many platforms told us that they encourage orphan clients to find a new adviser or switch to a [direct-to-consumer] platform, some platforms also charge orphan clients extra fees, of up to 0.5 per cent on top of their pre-existing platform charges."
One of the problems the FCA encountered was that, with one exception, platforms do not actively monitor whether there has been any activity on their customer accounts with ongoing advice charges.
The watchdog is considering imposing a requirement on platforms to check, if there is no activity on a client's account after a year, that they are still receiving an advice service.
But Ben Hammond, principal consultant at platform consultancy Altus, agreed with platforms they were likely to incur extra costs for dealing with an orphaned client.
He said most of the tasks will be quite small, such as dealing with clients requiring statements, but those costs are real "and it depends on the business model of the individual platform as to whether they pass that charge on".
Quilter currently has 10,000 orphaned clients, the highest number of the platforms Financial Adviser spoke to.
Standard Life said fewer than 3 per cent of its total client book across the platforms it runs were orphaned, equating to 5,500 clients.
Royal London had 695 orphaned clients at the end of July, the last month for which data is available.
Alastair Cunningham, financial planning director at Wingate Financial Planning said: "If the service provided by the platform is the same, and no advice is being given by the platform, I cannot see why a non-advised client should pay more. That seems very sharp practice to me."
The Financial Conduct Authority (FCA) has not responded to a request for comment.
david.thorpe@ft.com
