IFAs using network support provider Paradigm Financial Advisers face delays of up to two weeks for their cases to be checked and approved because of "unexpected" demand for the service.
Unlike some other networks, Paradigm pre-approves every piece of advice given by its member advisers. It promises to do this within 24 hours.
However, Paradigm director Anthony Morrow said "an upgrading of procedures" as well as "a greater than expected level of activity by Paradigm advisers" in September has caused delays.
Some advisers said they have been waiting for two weeks for approval of files in order to recommend products.
Others say they have had poor communication from Paradigm on the issue and regret engaging with the firm.
Morrow said the backlog is expected to be cleared over the next few weeks.
In an email to appointed representatives, seen by IFAonline, Morrow admitted the backlog has become serious and said the company is working to resolve it.
"We continue to progress through the file review backlog as a priority," he wrote.
"However through regular monitoring of the results over the course of this week and from the feedback received from our customers, we acknowledge the need to increase the rate of our approvals and response times.
"We have reassessed all outstanding cases and have adopted a risk-based approach, based on the past performance of advisers' submissions.
"We will increase the team resource to assist with both the backlog and the ongoing management of the new submissions and have commenced the recruitment of additional full time file checking staff."
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