This webpage, which google has dated as published in 2001, http://www.bitboost.com/ref/international-address-formats/new-zealand/, shows an example using wellington as 6004.

That link not working, and yes I've now been told that 6004 was the old code ... thanks.

If i remember correct (which i could be totally wrong) it was more about "using" postcodes than changing them.  I remember a big thing years ago saying that letters etc now need post codes.  It could have been that people were thinking they were new/different as they never really used them before.

Ours changed a few years back. Can't remember when, but it used to be 1240, and is now 1081.

Mine changed form 1007 to 0600

They did change, they used to be sort codes, not post codes. Only used for bulk mail senders to group things together to get the lower rates.

Rickles:

 

Does anyone recall what the old Post Code for central Wellington was?

 

It is now 6011, but I need the old code to answer a security question    I seem to remember a 4 being in it.

 

I'm sure I used to use 6001 for Lambton Quay Area toward Willis end.