The SMB CRM Migration Checklist: Switch Without Losing a Single Lead

July 30, 2026 · 11 min read · AI CRM

Migrating CRMs scares owners for one reason: fear of losing pipeline. Here's the exact checklist we use with Legion customers.

Every owner considering a CRM switch has the same nightmare: they cut over, three deals disappear into a field mapping bug, and the next month's revenue takes the hit. That fear is legitimate, and it's why so many businesses stay on tools they've already outgrown. The good news is that CRM migration is a solved problem if you follow a specific sequence. Below is the checklist we use with every Legion customer switching from another platform.

The golden rule of CRM migration

Never turn off the old system before the new system has been in production for at least a week. Run parallel. Data hygiene is impossible to verify without a live baseline to compare against.

Phase 1: Prep (days 1–3)

  1. Freeze non-essential changes in the old CRM. No new custom fields, no workflow edits.
  2. Document the top 10 workflows that must exist in the new system.
  3. Export the full contact database as CSV with every field.
  4. Export deals/pipeline with stage, value, owner, close date, and notes.
  5. Export call history and appointment history if your old CRM stored them.
  6. Export custom field definitions so you can recreate them.

Phase 2: Map (days 3–5)

  1. Create the equivalent custom fields in the new CRM before importing.
  2. Map each source field to a destination field. Document ambiguous ones.
  3. Standardize picklist values (e.g., "Med Spa" vs "medspa" vs "medical spa").
  4. Normalize phone numbers to E.164.
  5. Dedupe on phone + email; flag conflicts for manual review.

Phase 3: Stage & sample (day 6)

  1. Import into a staging workspace, not production.
  2. Sample 25 random records. Verify every field landed in the right place.
  3. Test the top 3 workflows end-to-end on the sampled records.
  4. Have an owner do the walkthrough. This is the last honest quality gate.

Phase 4: Integrations (days 7–9)

Before the cutover, wire up everything that produces or consumes leads:

  • Calendar (Google, Outlook, provider-specific).
  • Phone system, SMS provider, AI voice agent.
  • Website forms (change the endpoint, keep the old one live as a backup).
  • Ad lead-form connectors (Meta, Google, TikTok).
  • Payment or invoicing tool for closed-won triggers.

Phase 5: Parallel run (days 10–14)

  1. New leads flow into both CRMs. Old is source of truth for follow-up.
  2. Team runs daily reconciliation: does every lead in the new system also exist in the old?
  3. Fix mapping bugs immediately as they surface.
  4. Do not update deal stages in both systems — pick one for the parallel week.

Phase 6: Cutover (day 15)

  1. Repoint inbound routing (calls, forms, ads) exclusively to the new CRM.
  2. Set the old CRM to read-only.
  3. Freeze creation in the old CRM but keep it accessible for reference.
  4. Announce the cutover to the team in writing with the escalation path.

Phase 7: Post-cutover (days 15–90)

  1. Daily QA of new inbound flows for the first week.
  2. Weekly reconciliation for the first month.
  3. Keep the old CRM alive but read-only for 90 days as an insurance policy.
  4. After 90 days, export a final archive and shut down billing.

The rollback plan (nobody talks about this)

Before cutover, write down the exact steps to reverse. It's rarely needed, but knowing you can roll back in an hour changes the psychology of the entire migration.

Want to see it live? Book a 30-min Legion AI demo.