A teacher from a top Auckland school has admitted using colleagues' personal details to swindle more than $67,000.

Ex-Auckland Grammar School economics, accounting and business studies teacher Rafe Callum Fannin, 36, pleaded guilty to 13 charges at Auckland District Court this morning.

Police initially charged Fannin with four counts of dishonestly using driving licences, in the names of people he worked with, to gain a pecuniary advantage.

Two weeks later they added nine further charges, most of which covered the defendant dishonestly obtaining credit cards.

Fannin could face up to seven years in jail and Judge Anne Kiernan said a key issue at sentencing would be how much of the $67,000 he could pay back.

She ordered a probation report be completed that would look at all types of sentences, including home detention.

Between September last year and June this year, Fannin unlawfully got hold of credit cards from various financial institutions - ANZ, BNZ, American Express, GE Money and Kiwibank - in the names of other people.

Two of the four complainants named in court documents worked in the same department as the defendant at the prestigious all-boys school in Epsom.

At his first appearance he said Auckland Grammar were aware of the criminal proceedings and had stood him down.

Fannin has refused to comment since his first appearance when outside court he accepted he was "f***ed".

Fannin's bail conditions restrict him to living at his mother's house in Whangarei, surrendering his passport to authorities and not applying for any other travel documents.

He will be sentenced in October but before then there may be a restorative-justice conference, which would see the 36-year-old sit down with those he formerly taught with.