IP Whitelisting

Is it possible to provide an IP range that we can whitelist for the Companies House API? Internet access is blocked from our gateway by default, and so we need to provide an IP address or IP range we can whitelist to enable access.

Unfortunately we cannot.
We are not in control of IP addresses (or their ranges) for entry points into our services.
They are NOT fixed either.
If you need current IP addresses, I am sure you could ‘look them up’ using appropriate tools.
There will be more than one address of course.
They can change of course.