The property lender provides short-term loans for developers and entrepreneurs and offers first charge, bridging and mezzanine finance.
Loan amounts range from £250,000 to £5m and have a maximum loan-to-value of 70% with a maximum term of 364 days.
Michael Dean, principal at Avamore Capital, said joining the association was an affirmation that the lender was applying best practice to operations.
“We hope this will give brokers even more confidence in our abilities to deliver for their clients,” he said.
Benson Hersch, chief executive of the ASTL, said the association has continued to grow lender numbers since April 2011, when there were 18 members.
“It is positive to see that more lenders are choosing to set themselves apart by committing to operate according to a set of standards and ethics in order to give confidence to clients and brokers alike,” he said.
The ASTL recently reported that annual gross bridging lending reached £125.35m in the first quarter of the year, an annual increase of 56%.