How to Prepare Your Data for a CRM Migration to HubSpot

Migrating to HubSpot is exciting. You're leaving the old CRM behind, starting fresh, getting access to better tools. What's not to love?

I'll tell you what's not to love: migrating dirty data into a clean system and watching all your old problems follow you into your shiny new CRM.

I've managed dozens of CRM migrations. The single biggest predictor of migration success isn't the tool you're leaving or the complexity of your data model. It's whether you cleaned the data before you moved it.

The Golden Rule: Clean Before You Migrate

Every data problem you have in your old CRM will exist in HubSpot after migration, plus new problems created by the migration itself. Duplicates multiply. Formatting inconsistencies compound. Missing fields stay missing.

Cleaning data after migration is 3 to 5x harder than cleaning it before. In the old system, you know where everything is, what the fields mean, and what's garbage. In HubSpot, you're learning a new interface while trying to fix legacy issues. Don't do that to yourself.

The Pre-Migration Timeline

Start this process 4 to 8 weeks before your migration date. Rushing data prep is how migrations fail.

Weeks 1 to 2: Audit Your Current Data

• Record count: How many contacts, companies, deals, and tickets are you moving?
• Duplicate assessment: Run a dedup scan. How bad is it?
• Completeness check: What percentage of records have critical fields filled in?
• Custom objects and fields: Inventory every custom field. Document which ones are still in use.
• Junk records: Identify test records, internal contacts, bounced emails, and leads that never engaged.

The output of this phase is a clear picture of what you're working with and how much cleanup is needed.

Weeks 2 to 4: Clean and Standardize

1. Merge duplicates in the source system. It's easier to dedup where the data lives today.
2. Purge junk records: Delete test contacts, internal email records, bounced emails, and any record that has zero business value.
3. Standardize formatting: Normalize names (Title Case), phone numbers (consistent format), job titles (from your standardized list), and company names.
4. Fill critical gaps: Where possible, enrich records that are missing key fields (email, company, lifecycle stage, lead source).
5. Archive what you don't need: Not everything needs to migrate. Historical records with no future value can be archived, not moved.

Weeks 3 to 5: Map Your Fields

This is the most important technical step. Create a detailed field mapping document:

• Source field (name in your old CRM) -> HubSpot property (where it lands in HubSpot)
• Data type changes: Does a free-text field in the old system map to a dropdown in HubSpot? Document the value translations.
• Picklist translations: "Hot Lead" in Salesforce might be "MQL" in HubSpot. Map every value.
• Custom properties: Identify which HubSpot custom properties need to be created before migration.
• Fields to skip: Explicitly list fields that won't migrate and why.

Week 5 to 6: Test Migration

Never go straight to production. Run a test migration first:

1. Import a small batch (100 to 500 records) into a HubSpot sandbox or test dataset
2. Verify field mapping: does every field land where it should?
3. Check for new duplicates: did the import create records that overlap with existing HubSpot data?
4. Test associations: are contacts correctly linked to companies and deals?
5. Validate picklist values: did all dropdowns translate correctly?
6. Review a sample of records manually. Do they look right?

Week 6 to 8: Execute and Validate

1. Run the full migration during a low-activity period (weekend or after hours)
2. Validate record counts: did the right number of records make it over?
3. Spot-check 50 to 100 records across all object types
4. Test key workflows: do automation triggers fire correctly on migrated data?
5. Verify reporting: do dashboards show accurate data?
6. Have your sales team check their pipeline: do their deals look right?

Common Migration Traps

• Migrating inactive contacts: Don't pay HubSpot fees for 5,000 contacts who haven't engaged in 3 years. Purge before you move.
• Ignoring association quality: Contact-to-company and contact-to-deal associations break during migration if IDs don't map correctly.
• Skipping the test import: The number one cause of migration disasters. Always test first.
• Not communicating with your team: Your sales reps need to know what's changing, when, and what their records will look like in the new system.

For the ongoing data maintenance framework that keeps your freshly migrated data clean, read our Ultimate Guide to Data Hygiene. And if you'd rather have someone who's done this before handle the migration, that's what we do.