The instructions I have seen bear no resemblence to what I am actually supposed to do. The links do not work and it is impossible to work out where to enter label ranges or account details.
Also I can't seem to print test labels...
Interlink account can be integrated in Linnworks.net from Shipping > Integrations > Add Integration: http://www.linnworks.com/support/shipping-management/courier-integrations/interlink/interlink-add-new-integration
You need to have your Interlink User Name and Password.
Please note that you can only integrate this account using production details. If you have test account details, then account should be integrated in Linnworks desktop application. This will allow you to print test labels that should be sent to Interlink for verification. Once account is configured you will be able to integrate it in Linnworks.net.