By Richard Peck

When postcode began in 1967 the 2000 denoted the GPO Sydney, all Sydney city post offices and Sydney
city street deliveries. 2001 was for GPO Sydney PO boxes. 2002-2005 were not used. 2006 & onwards
were suburban POs.

When the private box separate postcodes in the 1000s were introduced, there were several for the
GPO and separate ones for city PO boxes. Often the PO also used these (eg, 1240 for Haymarket or 1225
for Royal Exchange). 2005 was used for Aust Post Headquarters in Strawberry Hills.

When the GPO boxes moved to Wynyard in 1996 they reverted to the 2001 postcode.

In 2006 postcode 2000 is used for the new PO at the World Square Tower and postcode 2003 only for
their private boxes.

And if you think this is complicated, Melbourne is even worse!