What happens if Australia Post changes their rates/pricing? Do I need to do anything?

No, there's nothing you need to do! You can leave it all to us. :) 

Rates on our app are live or what is called 'real-time'. This means that if Australia Post makes any change to its rates, it is reflected instantly at your checkout.  As an eCommerce partner of Australia Post, Addition's tech uses Australia Post's API, meaning that whenever they make changes to pricing, it'll come straight through to our app.