"It's been a Monty Python sketch for me. A normal person would wonder why I didn't chuck it all in and go home.
"I was committed to it, but you feel like you are a prisoner in an unfair system. It's very difficult."
The Government allocated $9 million last year to a package of measures to solve the teacher shortage, including a campaign to recruit teachers from Britain.
But some schools recruiting overseas said they were also being forced to jump through more official hoops to recruit them.
Auckland Grammar School principal Tim O'Connor said schools now had to advertise several times in New Zealand and prove that there were no suitable applicants in the country before they could recruit from overseas.
"We are having to justify to Immigration NZ the reason for appointing someone from the UK. That does take some time," he said.
"The other side is their qualifications. That is a time-consuming process that can take several months. It's an important step in the process that people have the right bachelor's degree or master's, and that their teaching qualifications match up."
Macleans College principal Byron Bentley said he employed teachers with a "limited authority to teach" while their qualifications were being verified.
An NZQA spokeswoman the agency received 660 applications to assess overseas teaching qualifications in the past six months, up 18.7 per cent from the previous six months.
"Of the 660 applications, we have processed 427 applications for international qualification assessments," she said.
"The remaining applications include those which were for 'teaching salary' purposes only, and those which came in towards the end of the six month period and are currently being processed."