The FCA revealed the firm had appointed Adam Stephens and Henry Shinners of Smith and Williamson LLP as joint administrators.
The regulator said the administrators would contact all affected clients “in due course.”
The FCA issued a scam warning, following the firm’s descent into administration, and told consumers to be on guard and to call the firm back on official numbers.
Greyfriars ceased to provide DFM services as of 31 March at which point clients transferred their portfolios out to an alternative provider or else became advisory clients of Greyfriars.
In some cases, client money and custody assets relating to the DFM services is still held by Greyfriars.
The FCA said these monies and assets were in the process of being returned.
Greyfriars sold its financial adviser business on 16 October to Insight Financial Associates Limited, which it said was writing to all advisory customers.
On SIPPs and SASS services, the regulator said the firm sold its business to Hartley Pensions Limited, which it also said would write to those SIPPs and SSAS clients subject to the deal.
The FCA said a previous transaction saw a number of Greyfriars SIPP customers transfer to Gaudi Regulated Services Limited.
On client money and assets an FCA statement read: “Greyfriars holds client money and custody assets for a small number of customers.
“Prior to entering administration, Greyfriars had notified these customers of its intention to return to them all client money and custody assets.
“As part of the administration, the administrators will carry out an assessment of the client money and assets held by the firm to confirm the current position.
“Following which, the administrators will continue the process of returning client money and custody assets to customers as quickly as possible.
“If the assessment of client money and assets results in Greyfriars clients not having all their money and assets returned, they may have access to the Financial Services Compensation Scheme, depending on their individual circumstances.”