The fear that keeps teams on a two-system setup is rarely the price; it is the suspicion that unpicking it will cost a fortnight of chaos. In practice the work divides into three parts, and only one of them needs care.
Your numbers
Business numbers are portable in most markets, but porting is a carrier process with its own paperwork, verification steps and lead time — it is not something any software vendor completes at the click of a button, and anyone promising a same-day switch is describing an exception, not the norm. The practical route is to keep your existing number live while the new setup runs beside it, so nothing depends on a port completing before your team can sell. Plan the number change as its own small project with a date, and do not let it gate the rest of the move.
Your history
Contacts, deals and open follow-ups import from CSV with field mapping, which is the part that matters — those records are what your reps work from tomorrow morning. Call history is a separate decision. Logged call outcomes and notes can be brought across with the contact records they belong to; raw recordings usually stay archived where they are, because teams almost never open a recording from nine months ago and retention obligations are satisfied by the original system. Decide deliberately what you need, rather than importing everything by default and cluttering fresh records with noise.
The parallel week
Run both systems for a week. New leads go into HelloGrowthCRM and are called, messaged and followed up entirely inside it, while the old stack keeps handling whatever is already mid-flight. By the end of the week you have a real answer to the only question that counts — whether your pipeline is more accurate and your follow-up more consistent in one system than in two — and you cancel the second subscription with evidence rather than hope.
