The firm had hoped to announce its intention to float in September, but postponed it after Peter Crook, the former chief executive of Provident Financial, stepped down from its board.
Cabot had planned to appoint Crook as its chairman in preparation for the London listing, the person said.
Crook's resignation from Provident Financial following an August profit warning also prompted him to leave Cabot, forcing the debt collector to find a replacement.
It is not known who Cabot will appoint in Crook's place.
Goldman Sachs, Morgan Stanley and Jefferies are managing the float of Cabot, which is owned by U.S. debt recovery business Encore Capital Group and JC Flowers.
They are targeting a 1 billion pound market capitalisation for the business.
A spate of companies have unveiled plans for London IPOs since the start of October, including ready meals supplier Bakkavor and power firm ContourGlobal.
(Reporting by Ben Martin; editing by Mark Potter and Jason Neely)
By Ben Martin