A move to Lark is a data project with a licence attached. This page is what we would tell you in the first meeting: what actually carries across, what does not, and what a sensible sequence looks like.
What moves
Carries across
Mail, with its folder structure and history, mailbox by mailbox
Files and shared drives, with their folder tree intact
The company directory, departments and reporting lines
Calendars, including recurring meetings and room bookings
Distribution lists and shared mailboxes, remapped onto groups
Documents, converted into Lark Docs where that is better than keeping them as files
What does not
Does not carry across cleanly
Every migration leaves a residue. It is cheaper to hear about it now than to discover it on cutover weekend.
Chat history from another platform rarely transfers in a shape anyone can use; we normally keep the old tool read-only for a period instead
Deeply nested permission models are usually redesigned rather than copied — copying them carries the problem across too
Macro-heavy spreadsheets stay as files. They do not become Base tables by themselves, and pretending otherwise is how a migration slips a month
Add-ins written for the old suite need an equivalent found, rebuilt, or dropped on purpose
Sequence
What a sensible plan looks like
Inventory — seats, mailbox sizes, file volume, and the integrations nobody remembers until they break
Tenant, domain, directory and permissions, proved on a pilot group before anyone else sees it
Mail and files migrated in waves, oldest data first, while the old system is still running
Cutover, with the old system left read-only rather than switched off
Then approvals, Base applications and the AI configuration — once people are in and working, not before
From you
What we need on your side
Administrator access to the current tenant, or someone in the room who has it
A named person who can decide what the organisation structure should be, because that decision is not ours to make
An honest list of the integrations in use, including the ones built by someone who has since left
Send us what you run today.
Headcount, current mail and file platform, rough data volume, and any integration you would be unhappy to lose. We will come back with a sequence and the parts we think are at risk.