I need to find a regular (once or twice a month) service from Bangkok to Australia for a 20kg box sized at approx 75cm x 50cm x 50cm.

I have used Thai Post in the past which gets there in around two weeks which is fine but it costs 7,400 baht. I would like to find something that cost around half of that if possible.

Any suggestions?

We use Fedex for small consignments. They had/have a special on for 25kg box - about $200AUD. We opened an account and sent several boxes per year on this rate. Payment terms with the account is 3 days.

You should be able to open the account online.

Good luck.