Some businesses in Christchurch are trying to become operational again for the first time since Tuesday's quake.
The Canterbury Employers Chamber of Commerce estimates that about 50,000 people will be unable to go into work in the cordoned-off central city area on Monday morning.
Some companies are relocating, such as Perpetual, which is moving to a one-storey office in Hornby.
Part of Pyne Gould Corporation, Perpetual was located in the company's building. Ten of its 49 staff are still missing.
Chief executive Patrick Middleton says it has eight other offices around the country that will be able to provide support for the Christchurch office.
Jade Software says about half of its 200 staff will be back at work on Monday. The rest will work from home or have relocated to Jade's other offices in Wellington and Auckland.
Chief executive Craig Richardson says its offices were cosmetically damaged but that has been repaired in the past few days, and it has power and water.
Other businesses, such as the law firm Duncan & Cotterill, which has 120 Christchurch staff, have people working from home.
Ernst & Young still looking
Financial consultancy Ernst and Young says it is still waiting for its building to be assessed and because of tough competition for alternative premises it's still looking for a new home.
It says it is diverting calls from its Christchurch office, and its branches in Wellington and Auckland will provide support.
Police say it is still too dangerous for people to return to work in the city centre. They say many buildings will have to be demolished, even though they are still standing.