Migrate the data, or start clean
What earns a seat in the new system, and what stays where it is.
Move what the business runs on: open records, live customers, balances, and anything a contract or a regulator says you keep. Leave the rest in a read-only copy of the old system. Moving everything is the default, and it carries the mess into a system bought to end it.
Work it out in a minute
Four answers. Prices what the overlap costs you, then says which way to go.
What we take on
Move what is open
Live customers, open jobs, unpaid invoices, current stock, anything a person will touch next week. That list is usually a fraction of the database and it is the part that has to be right.
Keep what you are required to keep
Tax records, contracts, employment files, anything a regulator or an agreement names. Kept does not mean migrated. A read-only copy of the old system satisfies it and costs a fraction of the work.
Leave the rest where it is
Closed jobs from four years ago, lapsed contacts, superseded quotes. They are evidence, not operating data, and they are the reason migrations run long and land dirty.
The archive is the answer to the argument
Somebody always says we might need it. A read-only copy of the old system, with a named owner and a date it can be retired, ends that conversation without moving anything.
Clean before you move, not after
Duplicates, dead contacts and half-finished records are cheaper to fix in the system that already holds them. Once they are in the new one they look like real data and nobody dares delete them.
Run both for one cycle
A month with the old system readable and the new one live is what catches the field nobody mapped. Switching off the day after the move is the version that produces the emergency.
How to decide what actually moves
Start from the work rather than the database. List what a person does in a normal week, and the records those actions touch. That list is what has to be in the new system on day one, and it is nearly always smaller than the export.
Then take the requirements separately. Tax, contracts, employment and anything regulated has a retention period. Those records have to survive, and surviving is a different requirement from being live and searchable in the new tool.
Everything else is history. History has value and it does not need to be migrated to keep it. A read-only copy of the old system, or an export in a format somebody can still open in five years, holds it for a fraction of the effort.
The reason to be strict is that data carries habits. A field somebody has been using for the wrong purpose since 2021 arrives in the new system with its wrong purpose intact, and the new system was bought to end exactly that.
Clean in the old system before the move, because the same records are easier to judge where they came from. In the new system they arrive looking official, and nobody wants to be the person who deleted a customer.
Plan one overlapping cycle. Close a month with both readable, compare the numbers, and switch off only when the two agree. The cost of a month of overlap is small next to the cost of finding a gap after the old system is gone.
Questions we get
How much history should we move?
Enough that a normal week does not need the old system. For most companies that is open records plus one or two years of closed ones, so a person can answer a question about last year without switching systems.
Anything older belongs in the archive rather than the new tool.
Can we just import everything and tidy later?
You can, and later rarely arrives. Once a record is in the live system it looks like real data, it shows up in reports, and nobody wants to be the person who deleted it.
The tidying is cheaper before the move, in the system whose habits produced the mess.
What about the old system, do we keep paying for it?
Usually for a while, at the cheapest tier, in read-only. Give it a named owner and a date it can be switched off, and put both in writing so it does not quietly renew for four years.
Where an export covers the requirement, take the export and stop paying.
Who decides what is required to keep?
Your accountant for the financial records and your lawyer for contracts and employment. Both answers are short and both change the plan, so ask before the scoping rather than during the move.
We build to whichever answer they give.
How long does a migration take?
It moves with the number of record types and the number of fields nobody can explain, not with the number of rows. Ten thousand clean rows are quick. Four hundred rows with a free text field holding six different meanings are not.
The mapping is the work. The transfer is an afternoon.
What breaks most often?
Attachments, dates and the field somebody repurposed. Files linked to records get missed because they live somewhere else, date formats flip between conventions, and the repurposed field arrives meaning nothing.
All three are found by closing one month in both systems and comparing.
More in the guides and every answer in one place.
Shaheer leads the work, with engineers, writers, filers and analysts behind him. C-suite operations for a San Francisco AI company, Six Sigma on the process side, Anthropic certified on the Model Context Protocol, ten years across eight industries. See what we have built