Guards could be removed from some Work and Income offices as part of an ongoing shake-up of security.

More than 200 additional guards were contracted for all the agency’s offices following last year’s Ashburton shooting, but staff have raised concerns about the “quality” of the guards.

A review's recommended further security changes, including ensuring the "effectiveness and efficiency" of security guards.

Social Development Minister Anne Tolley says security measures will be altered to the needs of different offices.

"We need to have a look at risk assessment at each individual site and then develop security provisions based on that risk assessment," she says.

"Some of the offices have more activity than others."

Ministry of Social Development CEO Brendan Boyle says visitors to Work and Income offices will definitely notice the difference.

"We went from one hundred and sixty security guards, which was effectively one at each Work and Income sites," he says. 

"We added another two hundred and fifty security guards, so there's a much stronger security presence at the office."

Boyle says there's also a zero tolerance policy towards threatening behaviour from clients.