Switching
Bring the client book. Leave the history.
Moving invoicing tools mid-year is mostly one CSV and one settings screen. The part worth getting right is the invoice series — a financial year gets one consecutive run of numbers, not a fresh one per tool.
Where are you coming from?
Two routes in.
Both take about ten minutes. Neither imports your past invoices — those stay where they were filed, which is also where the Income Tax Act expects them to stay for six years.
Switching
Import the list, set the next number, carry on.
Nothing is saved until you have seen exactly what will land — the import preview lists every column it could not place before you commit.
Founding cohort: free Pro through beta. No card needed.