The redundancies - which see director Roger Leboff and three account handlers leave the firm - mark the last in a long line of departures at GCI Financial, which at its height employed over 30 people and handled clients including fund manager Schroders.
Director Emily Morris, who has worked for GCI Financial for over three years, also leaves this month to join fund manager London and Capital as head of corporate comms.
GCI UK chief executive Adrian Wheeler said staff affected by the redundancies are currently in a two-week consultation phase, and that the company's remaining eight clients had been notified last week of the decision to close the firm.
GCI Financial MD Chris Smith - a former City stockbroker who was brought on board last December to try and salvage the agency - will remain with GCI UK as an independent consultant.
Wheeler said while GCI Financial has been wound down, the brand would continue: 'Regrettably, we have been driven to the conclusion that the potential of the City market this year does not justify keeping the full service agency (GCI Financial) running.
'We therefore radically downsized it, and this meant the involuntary loss of four jobs.'
Wheeler took control of the financial business last August after the departure of former CEO Philip Robinson.