Allianz Cornhill Insurance has warned brokers: if you keep sending us poor risks, we will refuse to deal with you.
Brokers reported receiving a "three strikes and you are out" letter from the insurer.
It warned that if it refused three consecutive risks, it would no longer do business with the broker. An Allianz Cornhill spokeswoman said branches dealt with these issues on an individual basis.
She confirmed the insurer had an "issue at certain locations from time to time" with "the broker who floods us with either round robins or inferior quality risks."
"So that the quotation service is not impaired to those who are working with us, we could refuse to quote for risks from brokers who are persistent offenders," she said.
"However, we would not cancel an agency agreement or refuse to do business solely over this sort of issue."