If your VoIP provider is one that allows calls to the emergency services, you will need to have configured and activated your emergency location. Please be sure to submit your correct and valid UK address as foreign addresses are not accepted.
By failing to do this, making an emergency call is not possible and could put you and your loved ones in jeopardy should an emergency occur.
Be aware that your VoIP provider will need to verify and validate your UK emergency address. This process can sometimes take a few days and you should receive an email confirming that access to the emergency services has been activated on your account. (Providing your emergency location has been validated by the EHA.)
Both 112 and 999 calls will pass to the emergency services here in the UK, if you follow the above steps. Should your VoIP provider be one that does not allow access to the emergency services, make sure you have other means of making calls to the emergency services, your life may very well depend on it.