Moving off spreadsheets: the migration checklist
A migration fails in the preparation, not the import. Work through this list before you move anything, and the switch takes days rather than weeks.
By Ayush Jain, Founder, grewray
Most migrations that go badly go badly for the same reasons: too much moved at once, duplicates carried across, and nobody checking the result until something is missing. This checklist prevents all three. Work through it in order. If you are moving to grewray, you can hand the export to us and we do the moving, but the decisions in the first two sections are still yours.
For why and when to switch at all, read when to move your business off spreadsheets.
1. Decide what moves
- List every spreadsheet and tool the business runs on today, and what each one holds.
- Mark what is live: current customers, open leads and quotes, active jobs, unpaid invoices, future bookings.
- Mark what is history: finished jobs, paid invoices, old leads.
- Decide how much history you need in the new system. Often the last year is plenty; the rest can stay in an archive you can still open.
- Choose a cut-over date, after which all new work goes into the new system.
2. Clean before you move
Moving messy data just moves the mess. For each sheet you are migrating:
- Remove duplicates. The same customer spelled three ways becomes three customers.
- Pick one format for phone numbers, dates and addresses, and apply it everywhere.
- Fill the gaps that matter: missing emails for customers you invoice, missing values on open leads.
- Split combined fields where you can, such as a full name into first and last, or an address into its parts.
- Delete what nobody needs: test rows, abandoned tabs, columns no one has filled in for a year.
3. Export
- Export each sheet as CSV or as the spreadsheet file itself.
- Keep one header row with clear column names.
- Export open invoices with their numbers, amounts, dates and what has been paid.
- Export open jobs with their stage, and any milestones already billed.
- Save a read-only copy of every original, dated, before you change anything.
4. Map the fields
Before importing, match each column to where it belongs in the new system:
| Your column | Where it goes |
|---|---|
| Client, Company | Contact and company |
| Site address | The client's site |
| Stage, Status | Lead stage or job stage |
| Quote value | Lead value |
| Invoice no., Amount, Due | Open invoice |
| Anything particular to your trade | A custom field |
Anything without an obvious home usually becomes a custom field, so it is not lost.
5. Import in the right order
Records depend on each other, so the order matters:
- Contacts and companies.
- Sites and addresses.
- Leads and open quotes.
- Jobs, linked to their clients.
- Open invoices, linked to their jobs.
- Future bookings.
6. Check it arrived
Do not take the import on trust. Check:
- Counts: the number of customers, open jobs and unpaid invoices matches the originals.
- Totals: the sum of unpaid invoices matches what your old records say is owed.
- A sample by hand: pick ten records at random and compare every field.
- The edge cases: the customer with two sites, the job with a change order, the invoice paid in part.
With grewray's migration, you review everything inside grewray before your first payment, which is the whole point of doing it this way.
Common problems, and how to fix them
| Problem | Cause | Fix |
|---|---|---|
| Duplicate customers | The same person in several sheets | Merge in the spreadsheet before you export |
| Dates imported wrongly | Day and month in different orders | Use one date format, such as 2026-09-25, everywhere |
| Phone numbers lose their leading zero | The sheet stored them as numbers | Format the column as text before exporting |
| Invoices without a customer | The name was spelled differently | Match invoice names to the contact list first |
| Totals that do not match | Part payments were not recorded | Export what has been paid, not just what was billed |
Who should do what
A migration goes faster with clear roles, even in a two-person business.
- The owner decides what moves, what the cut-over date is, and signs off the result.
- Whoever keeps the books checks the invoice totals and what is owed.
- Whoever runs the schedule checks future bookings and open jobs.
- The team tries the new system on real work in the first week and reports anything that looks wrong.
If grewray does the migration for you, our engineers do the moving and the mapping; your part is the decisions and the final check.
7. Switch over
- Tell the team the cut-over date and what changes for each of them.
- From that date, all new work goes into the new system.
- Freeze the old spreadsheets as read-only. Do not keep editing both.
- After two weeks, check that nothing is still being done the old way.
Moving history later
If you left older records behind on switch day, you can bring them across in batches once the new system is running: last year's finished jobs, then paid invoices, then old leads. Each batch follows the same steps, clean, export, map, import and check, but with no pressure, because nothing live depends on it. Many businesses find they rarely look at the old records, and leave them in the archive for good.
8. Keep your exit open
A good system lets you leave as easily as you arrived. Before you settle in, confirm you can export everything again, in open formats, whenever you like. In grewray, exporting is free and always available, with no notice period.