How to Migrate to a New CRM Without Losing Data: A Step-by-Step Plan

To migrate to a new CRM without losing data, export and back up everything first, clean duplicates and bad records, map old fields to new ones, run a small test import, review the results by hand, then do the full import and verify record counts before you turn off the old system. Keep the old system read-only for a defined period in case you find gaps. Most data loss happens because of skipped backups, unmapped fields, duplicate chaos and attachments or notes that were not part of the export. A small team with tidy data can complete a migration in a few weeks; messy data and many integrations take longer.

This guide gives a sequenced plan, a timeline and a list of risks. It is vendor-neutral, because each product has its own import tools and limits that you should read in its help documentation.

Phase 1: Plan the scope (days 1 to 3)

1. Decide what to move. Contacts, companies, deals, notes, activities, tasks, files, email history, custom fields. Not everything deserves to move. Ten-year-old dead leads may not be worth importing, and in a contact-based pricing model they can raise your bill.
2. Name an owner. One person is accountable for the migration and signs off on the result.
3. Set a cutover date. Choose a quiet period rather than the end of a sales quarter.
4. Inventory integrations. List every system connected to the old CRM: email, forms, billing, support, marketing, phone. Each needs a new connection.
5. Check the new vendor's import limits. Look at file size, supported formats, rate limits, which objects can be imported and how duplicates are handled.

Phase 2: Back up and export (days 3 to 5)

• Export every object to CSV or the format your system supports, and store copies in two secure locations with restricted access.
• Record the number of records per object. These counts are your reconciliation baseline.
• Export attachments and notes separately if they are not included. Some systems require a separate process for files and email history.
• Document custom fields: names, types, picklist values and required status.

Phase 3: Clean the data (days 5 to 10)

Cleaning before import is cheaper than after.

• Deduplicate. Match on email, phone and company name. Decide which record survives and merge notes.
• Standardize. Use consistent formats for phone numbers, states, country names and company suffixes such as "Inc." and "LLC".
• Fill essentials. Make sure each contact has the minimum required fields, such as an owner and an email or phone.
• Remove or archive records that are bounced, unsubscribed or clearly obsolete. Keep unsubscribe and opt-out status so you do not email people who opted out. See the compliance guide.
• Normalize picklists. Merge variants such as "Webinar", "webinar" and "Web seminar" into one value.

Phase 4: Map fields (days 8 to 12)

Create a mapping table with old field, new field, data type and transformation. For example:

Decide how to carry over relationships: contacts to companies, deals to contacts, activities to deals. Imports often need parent records first, then children, in a defined order.

Phase 5: Test import (days 12 to 14)

Import a sample of 50 to 100 records, including edge cases: long notes, special characters, blank fields, duplicates and records with several relationships. Review each by hand. Check dates, time zones, currency values, owners and linked records. Fix the mapping and repeat until the sample is clean.

Phase 6: Full import and verification (days 14 to 18)

1. Freeze changes in the old system during the final export.
2. Import objects in dependency order: companies, contacts, deals, then activities and notes.
3. Compare record counts against your baseline. Investigate any difference, however small.
4. Spot-check at least 25 records across object types, comparing old and new.
5. Verify that integrations are connected and tested with real messages.

Phase 7: Parallel period and cutover (days 18 to 30)

• Run the new system as the primary one while keeping the old one read-only.
• Train users on the five or six actions they perform most. See the 30-day setup guide.
• Collect issues in one shared list and fix them in batches.
• When the issues list is quiet, archive the old export and cancel the old subscription, respecting notice periods in the contract.

Common causes of data loss

• No backup before the import.
• Imports that overwrite existing records instead of creating new ones.
• Fields truncated because the new field has a shorter character limit.
• Dates misread because of format differences, for example day-month versus month-day.
• Lost links between contacts and deals because the import order was wrong.
• Attachments, call recordings or email history left behind because they were not part of the standard export.
• Opt-out status not carried over.

Budgeting the project

Estimate hours for cleaning, mapping, testing and training, and add consultant or tool fees. Use the setup cost estimator. Remember to overlap the old and new subscriptions for a month.

Frequently asked questions

How long does a CRM migration take?

For a small team with clean data, a few weeks is realistic. Larger databases, many custom fields and multiple integrations take longer, and the cleaning stage is usually the biggest variable.

Can I migrate email history and attachments?

Sometimes. Some systems export notes and activities, while email bodies and files may require separate tools or may not transfer. Ask both vendors early.

Should I hire a consultant?

Consider it if you have complex data, custom objects or compliance requirements. For a simple contact and deal import, vendor guides and a careful internal owner are often enough.

Sources

• Federal Trade Commission — guidance on protecting customer data during business changes
• National Institute of Standards and Technology — data security guidance for small businesses
• U.S. Small Business Administration — operations and technology planning resources