It's down to the final four, the Flag Consideration Panel will reveal its top four picks for New Zealand's flag later this morning.

MORE: See the full 40 flag shortlist

The Prime Minister has already given them his tick of approval, describing them all as excellent.

Thomas Randall is editor of the Flag Institute's quarterly journal Flagmaster and says it's unique to have a democratic process, as flag changes typically follow revolution or government upheaval.

"I think it is also a very interesting and exciting opportunity to be part of that process" he said. "To think about whether the flag should change or not - a lot of people just don't have the opportunity to be part of a process like that."

He said we should remember to keep it simple.

"Simple enough that a child could draw it, not use too many colours, make sure it can be easily reproduced."

"And I think people should think about it flying from the flagpole, at the United Nations or Olympics or something like that."