After uploading leads to your campaign, you might find that no leads appear, or only some are added. This guide helps you identify and fix the most common upload issues.
After the upload completes, Instantly shows a banner message indicating what happened:
Success messages: Contacts uploaded!
Warning messages: The banner tells you exactly what went wrong.
For duplicates: Contacts uploaded. X email(s) already exist!
For leads without email addresses: "X missing or invalid email(s)
Email field is empty
Incomplete email address
Email address not in standard format
Issue 1: Duplicates Were Skipped
This happens when "Check for duplicates" was enabled during upload:
Leads already in other campaigns or lists were automatically skipped
Look for a banner after the upload: "Contact uploaded! x emails already exist!"
If you WANT to upload duplicates:
Re-upload your file
Uncheck "Check for duplicates" option before clicking "Upload all"
Complete upload. Duplicates will now be added
To verify duplicates: Search for a few "missing" leads in CRM > All Leads. If they exist in any list or campaign, they were skipped as duplicates
Issue 2: Missing or Invalid Email Addresses
Email addresses are mandatory for leads in the campaign. Invalid format emails are rejected during upload.
Missing emails: Look for a banner after the upload: "X missing or invalid emai(s)"
Row has data but email column is blank
Email cell is empty
Lead has name/company but no email
Invalid format:
john@ (missing domain)
@domain.com (missing username)
john @domain.com (space in email)
domain.com (just domain, no address)
Solution:
Review the Email column in your file and make sure that every lead has an email address using the correct format: [email protected].
When uploading, verify the Email column is mapped to "Email" (predefined variable), not "Do Not Import".
Issue 3: Duplicate Emails Within Your File
If your CSV or Google Sheet contains the same email multiple times, Instantly automatically removes duplicates.
Step 1: Identify duplicates
Use spreadsheet tools to find duplicates.
In Google Sheets: Select "Email" column → Data → Data cleanup → Remove duplicates
In CSV/Excel: Select "Email" column → Data → Remove Duplicates
Step 2: Re-upload
Re-upload to the campaign, and verify all unique emails are uploaded.
Issue 4: File Formatting Issues
First row isn't headers (Email, First Name, etc.)
Column names must be under 20 characters
No special characters
No duplicate columns
Keep only one sheet in the file
Solution
Step 1: Add/fix header row
If missing headers, add column names to the first row: Email, FirstName, LastName, etc. Keep names simple and under 20 characters.
Step 2: Check duplicate columns
There shouldn't be two columns with the same header.
Step 3: Check file encoding
In Excel: File → Save As → Format: "CSV UTF-8 (Comma delimited)"
In Google Sheets: File → Download → CSV (.csv).
Step 4: Re-upload cleaned file
Save properly formatted CSV, upload to campaign, verify headers map correctly, and check all leads upload successfully.
Issue 5: Leads on Blocklist
Why this happens:
Emails on your blocklist are automatically skipped.
Domains on your blocklist will skip all email addresses from that domain
If leads should NOT be blocked:
Review blocklist: Find the blocked email or domain in the blocklist
Remove from blocklist: Delete the entry
Re-upload leads: Upload CSV again, and previously blocked leads will now upload
Issue 6: Whitespace in Data
Extra spaces, tabs, or special charaters can cause upload failures
Use the "Trim whitespaces" feature in your spreadsheet (Data → Data cleanup → Trim whitespaces) and try uploading again.
If the error persists
Use Find & Replace (Ctrl+H or Cmd+H).
In the "Find" field, paste the zero-width space character
Leave "Replace with" empty
Click "Replace All"
Save the cleaned file and re-upload. Walkthrough video
