Is there a way to bypass Shopify billing for courier services?

[ParcelNinja]

Hi,

We have a shipping/courier platform which compares courier prices in real-time and prints the labels for a particular shipment. We want to give this away for free, as it promotes another business of ours indirectly.

The issue is we need to pay the couriers/carries/postal services on your behalf, and if we run this billing through Shopify, we end up losing that margin. 

I've requested an exemption from Shopify, but I just want to confirm if I am correct in assuming the exemption - or am I doing something wrong?

Thanks in advance.