✓ TestedWorks with CSV, Excel, Google Sheets → JSON-LD Schema
By dataclean.to team · 2026-02-12
Constant Contact accounts accumulate duplicate contacts when subscribers sign up through multiple forms, get imported from different CSV files, or exist across several contact lists. The same person might appear on your newsletter list, event attendee list, and customer list as three separate contacts with slightly different details. dataclean.to scans your exported contact data to identify and merge these duplicates, reducing your contact count and ensuring each subscriber receives communications only once.
The Problem
Constant Contact's pricing is based on the total number of contacts in your account, counting the same email address on multiple lists as one contact but treating email variations as separate subscribers. A contact who signed up as jane@company.com on one form and Jane.Smith@company.com on another creates two billing entries. Beyond cost, duplicates cause subscribers to receive the same email campaign twice if they appear on two lists targeted by the same send. Bounce and engagement metrics become unreliable when activity is split across duplicate records. Constant Contact guide to managing contacts
How to Fix It
1
Export contacts from Constant Contact
Navigate to Contacts in your Constant Contact account and export all contacts or specific lists as CSV. Include email, first name, last name, phone, company, and list membership columns.
2
Upload the CSV to dataclean.to
Upload the exported contact file. The tool normalizes email addresses, compares names and phone numbers, and identifies contacts that appear to be the same person across different list memberships.
3
Review duplicate contact groups
Inspect each group of suspected duplicates. The tool shows list memberships, email variations, and field differences for each record so you can confirm they represent the same subscriber.
4
Merge duplicate contacts
Consolidate duplicate subscribers into single entries. List memberships from all duplicates are combined into the merged record. The most recently updated contact information is preserved as the primary entry.
5
Reimport the clean list
Download the deduplicated CSV and import it into Constant Contact. Add contacts to the appropriate lists and delete the old duplicate entries to bring your contact count and billing in line.
Frequently Asked Questions
Will merging contacts preserve list memberships?
Yes. When two duplicate contacts belong to different lists, the merged record includes all list memberships from both entries. No list assignments are lost during the merge process.
How does the tool handle email aliases?
The tool normalizes email addresses by removing Gmail dots and plus-aliases, lowercasing, and stripping whitespace. This means jane.doe+newsletter@gmail.com and janedoe@gmail.com are recognized as the same subscriber.
Can cleaning contacts reduce my Constant Contact bill?
Yes. Constant Contact charges by unique contacts. Removing duplicates reduces your total contact count, potentially dropping you to a lower pricing tier. The savings can be significant for accounts with thousands of duplicate entries.
Example: Input → Output
name
email
phone
city
status
Alice Johnson
alice@example.com
+1-555-0101
New York
active
alice johnson
ALICE@EXAMPLE.COM
5550101
new york
Active
Red rows show common data quality issues. dataclean.to normalizes and generates JSON-LD automatically.