The business received over £25.2m in new applications in June and achieved £17.6m in offers.
Director Tony Salentino said the whole business is receiving volumes not seen since before the 2008 downturn.
“This has been our best month since 2008 and I think I can now safely say that the industry has recovered a lot of the ground it lost when the credit crunch hit in 2008.
“Complete FS has probably the longest pedigree of consistent support for the intermediary market as we mark our first 21 years of service this year.”