What does Import Data from CSV/Excel cover?

Import Data from CSV/Excel explains migrate contacts, companies, and deals from spreadsheets or other crms. with practical setup and workflow guidance for revenue teams.

Who should read Import Data from CSV/Excel?

Sales, revenue, and customer success teams should read Import Data from CSV/Excel when they need a clear, implementation-focused workflow in Lumenbase.

How do I apply Import Data from CSV/Excel in Lumenbase?

Use the step-by-step guidance in Import Data from CSV/Excel and then apply the same flow directly in your workspace with your live records and tasks.

Import Data from CSV/Excel

101 · Step 4

Migration Guide

Migrate contacts, companies, and deals from spreadsheets or other CRMs.

By Sebastian StreiffertPublished Jan 10, 2026Updated May 29, 20266 min read

Overview: Importing Data into Lumenbase

Lumenbase's import wizard allows you to migrate your existing contacts, companies, deals, and invoices from spreadsheets or other CRM systems. Whether you're moving from Excel, Google Sheets, or another CRM, the import process handles field mapping, duplicate detection, and data validation automatically.

Supported Formats

Import from CSV (.csv) and Excel (.xlsx, .xls) files. Export from your current system in either format to get started.

Moving from a previous CRM with a full workspace copy? Use the migration wizard in Data Hub instead of CSV — see CRM workspace migration wizard.

Smart Field Mapping

The import wizard automatically suggests field mappings based on column headers, saving time and reducing errors during migration.

Duplicate Detection

Built-in duplicate detection identifies existing records that match your import data, with options to skip, merge, or create new records. Learn more aboutfinding and merging duplicates.

Supported Entity Types

You can import the following record types:

Entity Type	Key Fields	Duplicate Matching
Contacts	Name, Email, Phone, Company, Title	Email or LinkedIn URL
Companies	Name, Website, Industry, Size	Company name (case-insensitive)
Deals	Name, Value, Stage, Company, Contact	Deal name + company
Invoices	Number, Amount, Company, Date	Invoice number

Import companies before contacts if your contacts need to be linked to companies. Import contacts before deals if your deals reference contacts.

Preparing Your Data

Proper data preparation ensures a smooth import. Follow this checklist before uploading:

Data Preparation Checklist

Include a header row with descriptive column names
Remove duplicate rows from your source file
Standardize date formats (YYYY-MM-DD works best)
Clean up inconsistent data (e.g., 'USA' vs 'United States')
Ensure email addresses are properly formatted
Remove any formulas - save as values only
Split full names into first/last name columns if possible

Recommended Column Headers

Use these header names for automatic field mapping:

For Contacts	For Companies	For Deals
first_name, last_name	company_name	deal_name
email	website	value
phone	industry	stage
title	company_size	close_date
company	address	contact
linkedin_url	phone	company

Step-by-Step Import Guide

Follow these steps to import your data into Lumenbase:

Navigate to Imports

Go to System Operations → Imports in the sidebar. Click New Import to start the import wizard.

Select Entity Type

Choose what type of records you're importing: Contacts, Companies, Deals, or Invoices. This determines which fields are available for mapping.

Upload Your File

Drag and drop your CSV or Excel file, or click to browse. The wizard previews your data and detects column headers automatically.

Map Fields

Match your file columns to Lumenbase fields:

Required fields are marked with an asterisk (*)
Auto-detected mappings appear pre-selected
Click a column to change its mapping
Unmapped columns will be skipped
Map to custom fields if standard fields don't match

Configure Link Fields

For Contacts and Deals, configure how records link to other entities:

Contacts: Map a column to 'Company' to auto-link to existing companies
Deals: Map columns for linked company and primary contact
Matching is done by name - ensure names match existing records exactly

Set Duplicate Strategy

Choose how to handle records that match existing data:

Option	Behavior
Skip Duplicates	Existing records are left unchanged
Update Duplicates	Merge new data into existing records
Create All	Import all rows as new records (may create duplicates)

Review and Import

Preview the first few rows with your mappings applied. If everything looks correct, click Start Import to begin processing.

Duplicate Detection

Lumenbase automatically detects potential duplicates during import based on key identifying fields:

Matching Rules by Entity

Entity	Primary Match Field	Secondary Match
Contacts	Email address	LinkedIn URL
Companies	Company name (case-insensitive)	Website domain
Deals	Deal name + Company	-
Invoices	Invoice number	-

Duplicate Resolution Options

When duplicates are detected, you can:

Skip: Keep the existing record, don't import the duplicate row
Update/Merge: Combine data from both records (new data fills empty fields)
Create New: Import as a separate record despite the match

If you're not sure about duplicates, choose 'Skip Duplicates' for your first import. You can always do a second import with 'Update' to fill in missing data.

Handling Large Imports

Large imports (1,000+ records) are processed in the background using batch processing. Here's what to expect:

Progress indicator shows completion percentage
You can navigate away - import continues in background
Check System Operations → Import History for status
Failed rows are logged with specific error messages
Partially completed imports can be resumed

For very large imports (10,000+ records), consider splitting your file into smaller chunks. This makes it easier to identify and fix issues.

Troubleshooting Import Errors

Common Validation Errors

Error	Cause	Solution
Required field missing	Mandatory field not mapped	Map the required field or add data to your file
Invalid email format	Malformed email addresses	Clean email addresses before import
Date parse error	Unrecognized date format	Use YYYY-MM-DD or MM/DD/YYYY format
Number format error	Text in numeric fields	Remove currency symbols, commas from numbers
Company not found	Linked company doesn't exist	Import companies first, or create them manually

File Format Issues

Encoding errors: Save your CSV as UTF-8 encoding
Delimiter issues: Use comma-separated values, not semicolons
Extra columns: Remove blank columns from your spreadsheet
Merged cells: Unmerge all cells in Excel before exporting

After Import Fixes

If some rows failed to import:

Go to Import History and find your import
Download the error log to see which rows failed and why
Fix the issues in your original file
Re-import only the failed rows with 'Skip Duplicates' enabled

Best Practices for CRM Migration

Start with a small test import (50-100 rows) to verify mappings work correctly
Import in order: Companies → Contacts → Deals → Invoices
Back up your source data before making changes
Use consistent naming for companies to ensure proper linking
Clean and deduplicate data in your spreadsheet before importing
Document your field mappings for future reference
Assign a team member to review and verify imported data

Imports cannot be automatically undone. For large migrations, consider doing a test import in a separate workspace first.

Quick Reference

Start import: System Operations → Imports → New

View import history: System Operations → Imports (tab)

Download error log: Import History → [Import] → Errors

Supported formats: CSV, XLSX, XLS

Max file size: 50 MB per file

Recommended batch: 5,000 rows per import

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Every serious CRM was built decades ago and never fully rebuilt.

Import Data from CSV/Excel

Overview: Importing Data into Lumenbase

Supported Formats

Smart Field Mapping

Duplicate Detection

Supported Entity Types

Preparing Your Data

Data Preparation Checklist

Recommended Column Headers

Step-by-Step Import Guide

Navigate to Imports

Select Entity Type

Upload Your File

Map Fields

Configure Link Fields

Set Duplicate Strategy

Review and Import

Duplicate Detection

Matching Rules by Entity

Duplicate Resolution Options

Handling Large Imports

Troubleshooting Import Errors

Common Validation Errors

File Format Issues

After Import Fixes

Best Practices for CRM Migration

Quick Reference

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Every serious CRM was built decades ago and never fully rebuilt.

Import Data from CSV/Excel

1.Overview: Importing Data into Lumenbase

Supported Formats

Smart Field Mapping

Duplicate Detection

2.Supported Entity Types

3.Preparing Your Data

3.1.Data Preparation Checklist

3.2.Recommended Column Headers

4.Step-by-Step Import Guide

Navigate to Imports

Select Entity Type

Upload Your File

Map Fields

Configure Link Fields

Set Duplicate Strategy

Review and Import

5.Duplicate Detection

5.1.Matching Rules by Entity

5.2.Duplicate Resolution Options

6.Handling Large Imports

7.Troubleshooting Import Errors

7.1.Common Validation Errors

7.2.File Format Issues

7.3.After Import Fixes

8.Best Practices for CRM Migration

9.Quick Reference

Overview: Importing Data into Lumenbase

Supported Entity Types

Preparing Your Data

Data Preparation Checklist

Recommended Column Headers

Step-by-Step Import Guide

Duplicate Detection

Matching Rules by Entity

Duplicate Resolution Options

Handling Large Imports

Troubleshooting Import Errors

Common Validation Errors

File Format Issues

After Import Fixes

Best Practices for CRM Migration

Quick Reference