While most exporters are celebrating the weaker dollar, there is a flip side.

The New Zealand dollar has slipped below 66 US cents this morning, riding the coat-tails of a big drop in dairy prices overnight.

And Executive Director of Export NZ, Catherine Beard says this will make exports far more competitive in the international market.

But she says the complexity of the international supply chain will mean it will also come at a cost to some manufacturers.

'If you're manufacturing in New Zealand often you're importing components and things that's forming them and then re-exporting, so definitely upsides and downsides."