In October last year, Mr Guest, a Dunedin city councillor, was reinstated to the High Court's roll of barristers and solicitors.
Mr Guest said at that time he would be applying for the certificate and hoped to be practising as a lawyer again before Christmas.
Acting general manager of regulatory matters for the Law Society, Mary Ollivier, would not discuss Mr Guest's case specifically this week but said in cases where all references arrived promptly and "everything's perfect" a certificate could be issued "in a matter of days".
However, in other cases, the process could take months "if somebody has something that needs to be investigated".
"We have a committee called a fitness for practice committee that would look at some matters and then the board has the final say."
She would not comment on what stage had been reached in the processing of Mr Guest's application.
Under section 41 of the Lawyers and Conveyancers Act, the society can refuse to issue a certificate "on the ground that the person is not a fit and proper person".
When deciding who is "fit and proper" it can take into account more than a dozen factors including a person's character, any criminal conviction and where the person "is subject to an unresolved complaint".
Mr Guest, a former district court judge, was struck off in December 2001 on two counts of professional misconduct involving lying to a client and taking $25,000 more of her funds for costs than he was entitled to.
In July, he represented himself at a two-day hearing in front of the Lawyers and Conveyancers Disciplinary Tribunal, an arm of the Ministry of Justice, and argued he should be reinstated to the High Court roll.
The New Zealand Law Society opposed the application.
Society barrister Len Andersen said at the hearing Mr Guest had to demonstrate he was a fit and proper person to be reinstated and that he no longer "possesses the disqualifying character" which led to his being struck off.
"Assurances have been given in the past that have not been kept," he said.
In October, the tribunal overrode the Law Society's objection and announced Mr Guest was to be reinstated to the roll. According to the Law Society's website, that allows him, "like any non-lawyer", to provide legal services but not in the "reserved areas of work" such as representing or giving legal advice to anyone involved in court proceedings.
It allows Mr Guest to call himself an "enrolled barrister and solicitor of the High Court" but not a lawyer, law practitioner, legal practitioner, barrister, attorney or counsel.
To take on that role, Mr Guest requires a practising certificate - something only the Law Society, which opposed his reinstatement to the roll, can issue.
More than 11,000 New Zealand lawyers have a practising certificate.
When approached yesterday, Mr Guest said he did not want to comment.
"I'm busy on lots of other things. I'm really involved with the annual plan process at the moment."
Otago Law Society president Brian Kilkelly also declined to comment.
