Whether you are moving from spreadsheets to a CRM, switching accounts packages or replacing an old in-house system, the data migration is often the part that causes the most anxiety. A clear data migration checklist takes much of that worry away, and it matters: years of customer records, transactions and history need to arrive in the new system complete, accurate and usable.
Here is the data migration checklist we work through on our own projects. It applies whatever size your business is.
1. Take stock of what you have
- List every place data currently lives: databases, spreadsheets, email inboxes, paper files and other software.
- Identify who owns each source and who understands it.
- Estimate volumes: how many customers, jobs, products or invoices.
- Note any data that is regulated or sensitive, such as personal or financial information.
2. Decide what actually needs to move
Not everything needs to come with you. Decide how much history the new system needs, what can be archived elsewhere for reference and what can be deleted, taking into account legal retention requirements and UK GDPR. Migrating less data is faster, cheaper and leaves you with a cleaner system.
3. Map old fields to new ones
Create a simple mapping document showing where each piece of old data will go in the new system. This is where hidden data migration problems surface: a single “name” field that needs splitting into first and last name, free-text dates in different formats, or status values that do not match the new system’s options. Agree how each case will be handled before any data is moved.
Photo by Albert Stoynov on Unsplash
4. Clean the data before you move it
A data migration is the perfect opportunity to tidy up, and moving messy data simply moves the mess. Typical clean-up tasks include:
- Merging duplicate customers and contacts.
- Standardising addresses, phone numbers and postcodes.
- Filling or flagging missing required fields.
- Removing test records and obviously out-of-date entries.
5. Run a trial migration
Never let the first attempt be the real one. Run a full trial into a test copy of the new system, then check it carefully:
- Do record counts match between old and new?
- Do totals, such as outstanding balances, add up?
- Pick a sample of records and compare them field by field.
- Ask the people who use the data every day to look through it. They will spot problems that a script cannot.
Fix what you find, refine the process and repeat until the trial runs cleanly.
Keep a simple log of every trial run: what was moved, how long it took, what failed and what was changed. By the final run, that log becomes your step-by-step plan for the real thing.
6. Plan the cut-over
- Choose a quiet period for the final move.
- Agree a “freeze” so no new data is added to the old system during the switch.
- Take a full backup of the old system before you start.
- Write down a rollback plan in case something goes wrong.
- Tell customers and staff in advance if there will be any interruption.
7. Check, support and switch off carefully
After go-live, repeat your checks on the live system and give staff an easy way to report anything that looks wrong. Keep the old system available in read-only form for a while, so people can look things up if needed, before finally decommissioning it and securely deleting any data you no longer need.
Putting this data migration checklist into practice
A well-run migration is mostly careful planning and checking, but it does require technical skills to extract, transform and load data reliably, especially from older systems. Our data structure and migration service handles this end to end, from the first audit to final sign-off. If you have a data migration coming up, we would be glad to help you plan it.
