Learning Objective
By the end of this guide, you'll know how to set up field mapping between HubSpot and lemlist, sync properties in the right direction, and import HubSpot contacts into lemlist so mapped fields populate automatically.
Why This Matters
Field mapping ensures data stays synchronized between HubSpot and lemlist automatically. Instead of manually updating custom properties or segmentation fields in both systems, field mapping syncs changes so the right value is available where you need it.
Prerequisites
Before you start:
lemlist and HubSpot integration connected
Admin access to lemlist (and access to the HubSpot properties you want to sync)
Custom properties/fields you want to sync identified
Understanding of which system should be the source of truth (HubSpot, lemlist, or both)
What Is Field Mapping?
Field mapping defines how data from HubSpot syncs with lemlist and vice versa. It tells the integration: “Sync this HubSpot property with this lemlist field.”
Example: A HubSpot property like “Graduation date” can be mapped to a lemlist custom field such as “Test Field”.
Result: Information like custom properties used for personalization or segmentation stays consistent between the two tools.
How Field Mapping Works
Sync directions
Field mapping supports three sync directions:
Bi-sync (default): Changes in either system update the other.
HubSpot Priority: HubSpot changes update lemlist. lemlist changes don’t affect HubSpot.
lemlist Priority: lemlist changes update HubSpot. HubSpot changes don’t affect lemlist.
Sync timing
Automatic sync: Changes sync automatically between systems.
Sync delay: Updates may take a few minutes depending on HubSpot rate limits.
Not retroactive: Field mapping impacts new data and future changes. Data imported before a mapping exists won’t automatically backfill.
Scenario 1: Sync Data from HubSpot to lemlist
Use case
You have a property in HubSpot and want that value available in lemlist for personalization.
Step 1: Access field mapping in lemlist
In lemlist, click your user profile (bottom-left), then select Settings
In Settings, go to Integrations → HubSpot, then open the Field Mapping tab
Step 2: Map a lemlist field to a HubSpot property
Find the lemlist field you want to populate (example: Test Field)
On the HubSpot side of that row, click the dropdown (Select a field)
Select the HubSpot property you want to sync (example shown: Graduation date)
Tip: You can also search for a property by typing in the selector (example shown searching “test” and selecting a matching property).
✅ Result: The selected HubSpot property is now mapped to that lemlist field, and future syncs/imports will populate it.
Common field mapping mistakes
Dropdown (picklist) mismatch
If you're mapping a dropdown field, the values in lemlist and HubSpot must match exactly — including capitalization. For example, TITLE and title are treated as different values, and the sync will fail if they don't match.
Best practice: Use single-line text fields instead of dropdowns wherever possible to avoid this issue.
Field doesn't exist in HubSpot
lemlist can only map to fields that already exist in HubSpot. If the property hasn't been created in HubSpot yet, the data has nowhere to go.
Always create the custom property in HubSpot before setting up the mapping in lemlist.
Field mapping is not retroactive
Field mapping only applies to data synced after the mapping is configured. Existing records won't be backfilled.
Map your fields before importing leads or launching campaigns.
Step 3: Import HubSpot contacts into your campaign to bring the mapped data
Open your campaign, go to Lead list, then click Import new leads
In the import modal, click CRM import
Under Import from CRM, choose HubSpot and click the Select HubSpot filter in list dropdown
Select the HubSpot list/filter you want to import (example shown: All contacts)
Click Continue
(Optional) Choose whether to enrich leads data, then click Confirm to finish the import
✅ Verification: After import, open a lead in lemlist and confirm the mapped lemlist field contains the value from the HubSpot property.
Step 4: Test the sync behavior (recommended)
Modify in HubSpot:
Update the mapped property on a HubSpot contact
Wait a few minutes
Check the corresponding lemlist lead field
Modify in lemlist (only if Bi-sync is enabled for that mapping):
Update the mapped field in lemlist
Wait a few minutes
Check the corresponding HubSpot property
Scenario 2: Push Data from lemlist to HubSpot
Use case
You want a value managed in lemlist (for example, a custom field you set during import) to update a HubSpot contact property.
High-level steps
Create (or identify) the destination HubSpot contact property you want to update.
Create (or identify) the source lemlist field/variable that will hold the value.
In lemlist Settings → Integrations → HubSpot → Field Mapping, map the lemlist field to the HubSpot property.
Set the sync direction to lemlist Priority (or Bi-sync if you want both systems to overwrite each other).
Import/launch leads so the sync can run on contacts present in both systems.
📚 Reference: HubSpot official doc on creating properties
Sync Direction Options
Bi-sync (default)
How it works: Changes in either system update the other.
Use when: Both systems should stay aligned and either team can edit the field.
HubSpot Priority
How it works: HubSpot changes update lemlist; lemlist does not overwrite HubSpot.
Use when: HubSpot is your source of truth (example: sales-owned qualification fields).
lemlist Priority
How it works: lemlist changes update HubSpot; HubSpot does not overwrite lemlist.
Use when: lemlist is your source of truth (example: campaign-owned fields you don’t want edited in HubSpot).
Best Practices
Map before importing - Set up field mapping before importing leads. Mapping isn’t retroactive.
Test with a small dataset - Import a few contacts first and verify the mapped field values.
Choose the right sync direction - Don’t default to Bi-sync if one system should be the source of truth.
Keep field naming clear - Clear naming reduces mistakes when selecting fields from dropdowns.
Prefer text fields over dropdowns - Single-line text fields are less likely to fail because of value mismatches between systems.
Troubleshooting
Property not syncing between systems
Fix: Confirm the field is mapped correctly in Settings → Integrations → HubSpot → Field Mapping. Check the sync direction. Wait a few minutes for HubSpot rate limits.
Sync only works one direction
Cause: The mapping is set to HubSpot Priority or lemlist Priority.
Fix: Change the sync direction to Bi-sync if you need two-way updates.
Field mapping not affecting existing contacts
Cause: Field mapping is not retroactive.
Fix: Re-import contacts (or trigger an update) after the mapping exists so values can be synced going forward.
Dropdown field not syncing correctly
Cause: The dropdown values in lemlist and HubSpot do not match exactly.
Fix: Make sure each option is identical in both tools, including capitalization. If possible, switch to a single-line text field instead.
Custom field can't be selected in lemlist
Cause: The destination property does not exist yet in HubSpot.
Fix: Create the property in HubSpot first, then return to lemlist and set up the mapping.
Important Notes
⚠️ Not retroactive: Field mapping affects new data and future changes.
⚠️ Sync delay: Updates may take a few minutes depending on HubSpot rate limits.
⚠️ Source of truth: Pick the correct sync direction per field to avoid accidental overwrites.