As far as I know there isn't a direct interface.

A lot of Australian sites are using my Zone Based Shipping addon:
http://www.concrete5.org/marketplace/addons/zone-based-shipping/...

Thanks JohntheFish!

I wll have a look at this addon

Last year I actually got about 80% of the way building a shipping method that uses Australia Post's API. I had it successfully retrieving postage values, but our client changed their mind late in the project with how they wanted to calculate shipping, so I didn't put the finishing polish on the package - from memory it needed some caching and more configuration options (there's actually a lot of options that Australia post can offer at times)

If there is a desperate need for this I can look at digging up the code, but it's something that will still take a fair bit of work to finish off.

Thanks for the reply. Anyone building a ecommerce site with C5 within Australia will want this Addon. If I knew how to build it I would. If you finish it, I will buy it plus many more Australians will too!