Can we apply IP filtering/Whitelisting to our SaaS instance?

Yes, we can add additional IP filtering for your SaaS instance should you require it, to do this please submit a product support request with the following information.

IP or IP's of the connections you wish to allow (81.147.5.55)

or 

IP range with CIDR notation of the connections you wish to allow (81.147.5.55/24)