Two partners at an Uxbridge practice have been given a six-month ultimatum to pay £14,000 in barristers fees.
The Solicitors Disciplinary Tribunal heard last week how Tony Foss and Clinton Worsfold, of Garner Foss & Worsfold, owed fees stretching back 10 years.
Gerald Lynch, representing the Law Society, told the tribunal that the debt at one point reached £19,000 but this was reduced during the lengthy dispute between the firm and the Bar Council.
Foss told the tribunal: "We both accept there are unpaid counsel fees and it is a liability we have now sought to amend.
"We have not profited. We have not received funds and kept funds. There are a number of cases where we have not been paid either but we accept our responsibilities."
The tribunal chairman, David Leverton, gave the solicitors six months to start paying off the debt and ordered costs of £1,264.
He said: "We expect you to make efforts to pay off a substantial amount of the fees owed to counsel but if you don't, the tribunal will take a far more serious view."
Mark Stobbs, secretary to the Bar's professional standards committee, said barristers had several ways of recovering unpaid fees, the ultimate sanction being withdrawal from the Bar Council's credit scheme.