One local person was able to hide 50 convictions.
To be eligible for a clean slate, a person must not only have been conviction-free for seven years, but not have received a custodial sentence, nor been convicted of a "specified offence".
Specified crimes include sexual offending against children and the mentally impaired, and can never be concealed.
Wairarapa Chamber of Commerce chief executive Stephanie Gundersen-Reid said while people deserved a second chance, employers should know about more serious convictions. Especially if it put them or the business in danger.
"It's very dependent on what the conviction was for. Fraud is a biggie for businesses and drugs and assaulting anyone is up there, in my [opinion]," she said.
"Even with drink-driving ... if you've done it six times then you're obviously a slow learner."
Employers respected applicants who were honest about their past.
Nationally, 115,079 eligible people have been clean-slated since November 2004.
One Auckland person who was able to conceal former crimes had racked up a staggering 282 convictions.
Business New Zealand chief executive Phil O'Reilly said employers should always be able to see an applicant's history.
"If you've had a dishonesty offence and a small retailer is going to employ you behind the cash till, that's directly relevant, whether it's one or 282," he said.
"For many small businesses that's their income, it's them and their house and the wellbeing of their family that's at stake."
However, Pathways Trust reintegration manager Carey Ewing said the clean-slate law allowed former criminals to put their mistakes behind them.
"New Zealand can be a particularly unforgiving environment [and] I don't think any of us would like to live a life where we were solely judged upon the mistakes we made in the past."
Exaggerated media coverage of criminal offending had helped fuel the belief that people didn't change and the longer the jail term, the better, he said.
A clean slate gave someone opportunities that public opinion would not.