Can I migrate from the CRM I use now?
Usually — and if not, you are told on the scoping call rather than afterwards.
What you are on now is looked at during the scoping call. If it can be exported, contacts, enquiries, listings and the history attached to them are brought across.
Some systems cannot be exported. When that is the case you are told on the call, before anything is agreed, rather than discovering it during the build.