TL;DR: Check the lead import limit for your import method before adding leads to a lemlist campaign. This helps you avoid failed imports and split large lead lists the right way from the start. Takes about 2 minutes to review.

This article is helpful if you are:

• Setting up your first campaign and planning how to import leads
• Working with large lead lists through CSV, API, or CRM integrations
• Using the Chrome extension to import leads from LinkedIn or Sales Navigator

Lead import limits in lemlist vary depending on how you add leads. Knowing the right limit for CSV upload, API import, HubSpot, Pipedrive, Salesforce, or the Chrome extension helps you avoid errors and organize campaigns more efficiently.

Import limits depend on the source you use to add leads:

• CSV lets you upload large lists, but campaigns are capped per batch
• API supports larger campaign limits, but leads are added one by one
• CRM integrations have lower campaign limits than API imports
• Chrome extension imports have separate limits based on the source platform

Choose the import method that fits both your lead volume and how you want to organize campaigns.

1. Identify how you want to import leads into lemlist.

Choose from CSV upload, API, HubSpot, Pipedrive, Salesforce, or the Chrome extension.

2. Match your import method to the correct limit below.

You can upload up to 40,000 leads total via CSV, split into batches of 10,000 leads per campaign.

You can add up to 40,000 leads per campaign via the API. Each lead must be added one at a time, which means every lead requires its own API call.

You can import up to 10,000 leads per campaign using the HubSpot or Pipedrive integrations.

You can import up to 2,000 leads per campaign using the Salesforce integration.

If you use the Chrome extension, the limit depends on the source:

• 999 leads from LinkedIn
• 2,500 leads from Sales Navigator

3. If your lead list is larger than the limit, split the leads across multiple campaigns.

This helps you stay within the import cap and makes it easier to manage outreach performance.

4. Keep campaign size manageable to protect deliverability.

Even when a larger import is allowed, smaller and better-targeted campaigns usually perform better and help protect your sending reputation.

✓ You know the exact lead import limit for your chosen import method
✓ Your lead list is split correctly if it exceeds the campaign limit
✓ You can plan campaign creation without hitting import errors
✓ Your campaign structure supports better deliverability and easier personalization

Issue: The import fails or stops before all leads are added

Root cause: The campaign or import method exceeds the allowed lead limit

Fix:
• Check the limit for your import method in this article
• Reduce the number of leads in the current import
• Split the remaining leads into one or more additional campaigns

Issue: You uploaded a CSV but cannot add the full file to one campaign

Root cause: CSV imports must be split into batches of 10,000 leads per campaign

Fix:
• Break the CSV file into smaller campaign-sized groups
• Import each group into a separate campaign
• Double-check that no campaign exceeds 10,000 leads

Issue: API imports are slower than expected

Root cause: API imports add leads one by one, not in bulk per request

Fix:
• Confirm your workflow supports one API call per lead
• Allow enough time for larger imports to complete
• If needed, review whether CSV upload is a better fit for large batches

Issue: You need to import more leads than one campaign allows

Root cause: Some import methods have lower per-campaign limits

Fix:
• Create multiple campaigns for different lead segments
• Distribute leads across those campaigns
• Ramp up gradually to keep deliverability healthy