According to the network, 26 registered individuals joined the network during lockdown, with five joining in May.
This brought the total number of advisers within the network to 693 across 340 firms, with 22 more advisers expected to be onboarded shortly.
Stonebridge also reported “positive levels” of new business activity during May, as the housing market reopened in England.
The number of mortgage applications processed during the month was 12 per cent ahead of budget, and the number of purchase mortgage applications increased by 55 per cent between April and May.
Rob Clifford, chief executive of Stonebridge, said: “To have materially increased our adviser numbers during this period is a fantastic result, down not only to the work of our recruitment team, but also those existing AR firms who are increasingly looking to add advisers to their businesses in order to meet demand.
“The easing of lockdown has undoubtedly had a positive impact on purchase activity levels and, while it is still early days, it has been very promising to see strong mortgage application numbers, particularly purchase cases, given the uncertainty about how consumers might respond."
However, the network does not plan to reopen any of its offices during June or July due to its “ongoing ability to maintain quality and service levels via a remote working arrangement”, as well as the continued risk of coronavirus.
Its offices in Basildon, Milton Keynes and Nottingham were closed on March 26.
Mr Clifford said: “That said, these do of course remain very challenging times, particularly as we navigate our way through this situation, and we seek to overcome the obstacles presented by product availability and lender caution.”
The network received more than 1,200 calls in May while working remotely, as well as carrying out 500 adviser calls and more than 60 remote training sessions.