A date for the appeal has not yet been set.
Mr Hart did not return phone calls today.
The former high-flying lawyer was found guilty of three charges of professional misconduct in July and was formally struck off as a lawyer last week.
The Tribunal - chaired by Judge Dale Clarkson - said striking off was a "last resort" for the senior lawyer who has represented clients at the Privy Council.
"We consider that the evidence in these proceedings has disclosed a lack of integrity on the part of this practitioner."
An aggravating factor was Mr Hart's "poor disciplinary history", which included seven previous findings against him.
One for "gross overcharging" was 30 years old, but identical in nature to the latest case.
Mr Hart was found guilty of unsatisfactory conduct for overcharging on two occasions in 2010 and again a year later.
Two other findings of unsatisfactory conduct for failing to pay expert witnesses, again described as identical behaviour to one of the charges in the current case, were made just last month.
The pattern of behaviour meant the tribunal had "no confidence in either his rehabilitation or protection of the public by ensuring there is no risk of reoffending".
"We accept that striking off, particularly in a practitioner of such seniority, is a last resort response," said Judge Clarkson.
"Having weighed all the evidence and submissions it is the tribunal's unanimous view that the practitioner is no longer a fit and proper person to practise as a barrister or solicitor."
The 71-year-old lawyer has also lost his multi-million dollar properties north-west of Auckland after owing $30 million to the ANZ National Bank. It has also been revealed that his fleet of luxury cars - including an Aston Martin - have been seized by debt collectors.
Mr Hart was ordered to pay 85 per cent of the Law Society's $116,000 costs - a total of $98,000.
