The merger's official, but change is set to continue for some months at the Government's new Ministry of Business Innovation and Employment.
The new ministry's been created from the merging of the Ministry of Economic Development, the Department of Labour, and the Department of Building and Housing.
Minister Steven Joyce says the financial and accounting systems are in place, but that's just the beginning.
He says further changes will happen over the next couple of months and should be in place by September or October.
Mr Joyce says so far the agencies are working together well across their formerly different boundaries.
Labour MP David Cunliffe says the merger's merely a reshuffling of deck chairs and an unnecessary branding exercise.
"People will still be sitting in the same offices, presumably doing much the same thing, yet the Government says this is the best thing since sliced bread for business.
"Well frankly the business people I've been talking to are pretty cynical about it. I don't think that life is going to change just because the logo on a Government department changes."