MyPost Business will not work in Shipstation with Australia Post credit accounts. IT will only work when each order is individually charged to a credit card. This means if you have 800 orders a month you will have 800 charges to your credit card rather than one entry to your Australia Post credit account that you can then pay. I get this is probably an australia post issue. BUT....
I can use MyPost business on the auspost website with my credit account. So I should be able to do same through shipstation. Currently we have to process orders through Australia Post and then copy/paste them to Shipstation so that all our shipping orders are in one place. When is Shipstation going to fix this issue.
Geoff