How to Migrate from Salesforce to HubSpot Without Losing a Single Record

Why CRM Migrations Go Wrong — and How to Stop It Happening to You

Every year, UK businesses spend millions on CRM migration projects that end in data loss, missed deadlines, and frantic IT firefighting. The most common switch? Salesforce to HubSpot. And it's rarely smooth.

The core problem isn't the technology — both platforms are mature and well-documented. The problem is underestimating data complexity: legacy custom fields, multi-object relationships, attachment files, activity history, and years of duplicate records that nobody cleaned up. Drop any of that during migration and you'll spend weeks rebuilding what you lost.

This guide walks through the exact methodology 2-IC DATA SYSTEMS uses for every CRM migration UK client we take on — from discovery through to post-go-live reconciliation.

Phase 1: Discovery and Data Audit

Before a single record moves, you need to understand exactly what you have.

Audit Your Salesforce Schema

Start by exporting a full schema inventory: every standard and custom object, every field, every relationship. Salesforce's Schema Builder helps visually, but for migration purposes you want a flat export you can annotate.

Key questions to answer:

• Which objects are actually in use? (Many tenants have abandoned custom objects with thousands of dead records.)
• Which fields are populated for less than 10% of records? (These may not need migrating.)
• What are the critical relationship chains — e.g., Account → Contact → Opportunity → Activity?

Classify Your Data

Group records into three buckets:

1. 1.Migrate as-is — clean, active, business-critical records
2. 2.Transform before migration — records that need enrichment, deduplication, or field remapping
3. 3.Archive, don't migrate — historic records needed for compliance but not day-to-day operations

A common CRM migration UK pitfall is treating all three groups the same. Archivable records belong in a cold-storage export, not in your new HubSpot instance cluttering dashboards.

Phase 2: Field Mapping

HubSpot and Salesforce have very different data models. Salesforce is object-centric (Accounts contain Contacts contain Opportunities). HubSpot is contact-centric (Companies → Contacts → Deals). This matters enormously.

Map Each Salesforce Object to its HubSpot Equivalent

The trickiest part is Leads vs Contacts. Salesforce treats Leads and Contacts as separate objects; HubSpot merges them. Your migration strategy needs to decide: convert all Leads to Contacts at migration time, or map unconverted Leads to a lifecycle stage field in HubSpot?

Handle Custom Fields Explicitly

Every custom Salesforce field needs an explicit HubSpot destination. Options:

• Map to an existing HubSpot property with equivalent data type
• Create a new custom property in HubSpot (free)
• Drop it (document why)

Never rely on "auto-mapping" tools to make this decision for you. A single wrong mapping — say, mapping a currency field to a text field — will corrupt downstream reporting.

Phase 3: Dry-Run Validation

This is the step most DIY CRM migration UK projects skip, and it's the one that saves them.

Run a complete migration against a HubSpot sandbox (or a test portal you'll delete post-go-live). Then run reconciliation reports:

• Record count match: total Contacts in Salesforce export = total Contacts in HubSpot import
• Field completeness: for each mapped field, what % of records have a populated value in both source and destination?
• Relationship integrity: every HubSpot Contact has a valid associated Company; every Deal has a valid associated Contact
• Duplicate detection: run HubSpot's built-in duplicate finder on the imported data before merging anything

Fix issues in the transformation layer — not after go-live.

Phase 4: GDPR Compliance During Migration

Under UK GDPR (retained post-Brexit as the UK GDPR), transferring personal data between systems constitutes processing. You need a documented lawful basis.

For most B2B CRM data, the lawful basis is legitimate interests (Article 6(1)(f)), but you must document this in your Record of Processing Activities (ROPA). If you're moving EU resident data, check whether Standard Contractual Clauses are needed.

Practically speaking, before a CRM migration UK businesses must:

1. 1.Issue a Data Processing Agreement (DPA) with any third-party migration service (including 2-IC)
2. 2.Ensure the destination system (HubSpot) has appropriate security certifications (ISO 27001, SOC 2 — HubSpot holds both)
3. 3.Log the migration as a processing activity in your ROPA
4. 4.Confirm that any data subjects who have opted out of communications are excluded or flagged in the migrated dataset

Phase 5: Go-Live and Post-Migration Reconciliation

On migration day, you have two options: big-bang (flip overnight) or parallel run (both systems live for a transition period). For most mid-market CRM migration UK projects, parallel run for 2–4 weeks is safest.

Big-Bang Cutover

Best for smaller datasets (under 50k records) where the migration window is short and you can verify completeness quickly. Run the final delta sync, freeze Salesforce writes, import to HubSpot, verify row counts, go live.

Parallel Run

Best for complex migrations with many users and active pipelines. Both systems receive updates for a defined window. Users gradually shift to HubSpot. Delta sync runs daily until cutover.

Post go-live, run a final reconciliation report comparing the source Salesforce export to the HubSpot state. Flag any discrepancies. Most will be benign (records created or updated during the parallel window) but some will be genuine issues that need manual resolution.

Common Mistakes to Avoid

Not cleaning data before migration. Garbage in, garbage out. Deduplicate and enrich before you start mapping.

Migrating everything by default. Your new CRM is an opportunity to start fresh. Archive what you don't need.

Ignoring activity history. Emails, calls, and notes are often the most valuable data in a CRM. They're also the hardest to migrate. Plan for this explicitly.

Underestimating testing time. Budget at least as much time for testing as for the migration itself.

No rollback plan. Keep your Salesforce instance live and writable until you're certain HubSpot is correct. Migration without a rollback plan is a gamble.

Ready to Migrate?

2-IC DATA SYSTEMS handles CRM migration UK businesses can rely on — fixed price, zero data loss, full GDPR documentation, 12-week delivery. Whether you're migrating 5,000 or 500,000 records, we follow the same rigorous methodology described above.

Book a free migration audit — we'll review your Salesforce schema and give you a fixed-price proposal within 48 hours.