When you create a sandbox, everything is copied across apart from the data (Which is the problem I'm working on solving now).

This INCLUDES the webhooks. So our production server that receives the webhooks does not know if the webhook is coming from production or sandbox.

If there was an 'Organization ID' param, our webhook receiver will be able to tell if it's coming from production or a sandbox, without needing to go and disable/edit all the webhooks.