A quick question, would appreciate some clarification from those experienced NZ frequent flyers.

I've got a couple of trips in business class this year on Air NZ.

With regard to obtaining tier status, the Air NZ webpage states 450 status points to obtain Silver, 900 to obtain Gold, and 1500 to obtain Elite.

Are points compounding or do they reset to zero upon gaining a tier status, i.e once I have achieved Gold status do I then need to achieve a further 1500 points to achieve Elite, or once I have achieved Gold status (900 SP) then I need to earn a further 600 SP (900+600=1500) to achieve Elite?

Many thanks!