A report by the BBC Trust's Editorial Standards Committee upheld a complaint by a member of the public and found her appearances on the show had been too frequent since her promotion to the Labour front bench.
Ms Abbott, who was a regular on the show alongside sparring partner Michael Portillo, was named Shadow Minister for Public Health in October 2010.
She continued to appear on the show, billed as a former presenter, appearing eight times up to July this year, and declared earnings from the show of £6712. The investigation concluded she should have been paid what the BBC described as a "realistic" fee for her appearances on the show, broadcast on BBC1 at 11.35pm on Thursday nights.
BBC guidelines state it "should not normally pay MPs ... for appearances or other contributions to any BBC output in which they are speaking as a member of their party or expressing political views".