The firm, which questioned 345 platform users, found that 21 per cent of those were using discretionary fund managers to do this. Earlier research has found over half of all advisers, not just platform users, are outsourcing some or all of their investment process.
As RDR approaches, it is likely to act as a catalyst for more firms seeking to partner with discretionary managers.
However, firms need to treat DFMs as a long-term business relationship rather than a quick solution.
Fraser Donaldson, Defaqto's insight analyst for funds, said: "When looking to outsource to a DFM advisers need to treat the partnership as a long-term business relationship- robust due diligence is therefore critically important.

"However, the DFM space is crowded and propositions vary widely. As a result, it is understandably difficult for advisers to evaluate which solutions will best suit their business and client base."
There are also opportunities to DFMs who will need to present an appealing proposition to advisers. Appealing features include online valuations, Capital Gains Tax reports, consolidated Income Tax statements and facilitation of in-specie transfers out.
Mr Donaldson said: "To achieve the highest level of rating, propositions will need to demonstrate a high degree of dedication to the intermediated market, flexibility, transparency and high levels of personal and online service."
The firm has various star ratings on its site which rank 35 bespoke DFM services and 45 model portfolio services. To view the rankings click here