Each service has its own restrictions based on the volumetric weight of the parcel.
To find the restrictions for the service you prefer, click "More" at the top of this page; select the courier you want to use from the "Our Range of Courier Services" section and click the "Details" link next to the service you are interested in from the box on the right side of the page.
Alternatively, click "Buy This Service" from the quick quote results to see the specific restrictions listed in the service description on the right of the page for your preferred service.
How do I calculate my parcel's volumetric weight?
Why does the website say my parcel is too large for standard services?