In the last five days, five agents have been expelled by The Property Ombudsman, all over unpaid awards made to complainants.
The tally is on top of seven expulsions last month.
The latest expulsions are: A & A Star Estates in Finchley, London; Jennings & Kent in Erith, Kent; Alexander Reed in Isleworth, Middlesex; Blackhorse Property in Bradford; and Joseph Properties in Burnley.
All have sales and lettings businesses, and none will be able to trade legally because the only other redress scheme, PRS, will not accept them unless and until they make the payments ordered.
The expulsions are all for one year, with the exception of Jennings & Kent, which has been expelled for 18 months.
Alexander Reed was expelled for two years in May, but the latest notification says the expulsion will last an additional year.
A spokesperson for TPO said that reasons for the latest expulsions will be spelled out in publicly available information.