Bulk Contact Import Issue in Pabbly Chatflow .

Hi Pabbly Support Team,

We are using Pabbly Chatflow for WhatsApp communication for StarAndDaisy.

We need to import approximately 100,000 customer contacts into Chatflow for broadcast campaigns.

While importing the contact file, many/all contacts are not being added successfully to the contact list.

We have checked the mobile number format and are using numbers with country code, for example: 919876543210.

Please help us confirm:

1. What is the maximum number of contacts allowed in one CSV import?
2. Is there any limit on total contacts in a Chatflow account/contact list?
3. What is the recommended CSV format for importing around 100,000 contacts?
4. How are duplicate contacts handled?
5. Does the Opt-In field require a specific value such as Yes, True, or 1?
6. Is there any account-level restriction preventing bulk contact import?
7. Can you check our account/import logs and confirm why the contacts are failing?
8. Should we split the file into smaller batches, and if yes, what batch size do you recommend?

Our goal is to create a contact list of around 1 lakh opted-in customers and use it for WhatsApp broadcasts.

Please guide us on the correct import process and the required file format.

Thanks,

Hi Prachi,

Thank you for reaching out to Pabbly Support.

Below are the details and recommended best practices to help you successfully import your contact list for WhatsApp broadcasts:

1. Maximum contacts per CSV import: The system mentions: Upload your contacts file in .csv format. Upto 50MB file size(~200,000 lakhs contacts) is allowed. But for optimal performance, we recommend importing contacts in batches rather than uploading a single large file.

2. Total contact limit: There is no strict account-level limit on the total contacts in Pabbly Chatflow, provided your active plan supports your subscriber volume.

3. Recommended CSV format:

   • Phone Number: Must include the country code without any +, spaces, or special characters (e.g., 919876543210).

   • Headers: Standard headers like Name, Phone, Email, etc.

   • Encoding: Ensure the CSV file is saved.

4. Duplicate contacts: Duplicate numbers are automatically updated/merged based on the phone number field rather than creating duplicate entries.

5. Opt-In field requirement: Use boolean-style standard values such as 1, True, or Yes in the Opt-In column.

6. Account restrictions & import logs: There are no inherent account restrictions blocking bulk imports. Failures usually occur due to file formatting errors, special characters in fields, or request timeouts when processing very large files.

7. Recommended batch size: Yes, please split your 100,000 contacts into smaller files of 5,000 to 10,000 contacts per batch. This prevents browser/server timeout issues and allows for smooth processing.

Next Steps: Please try uploading a smaller batch (5,000 contacts) in the recommended format. If you still encounter failures, please reply with a sample CSV file (or first few rows) and a screenshot of any error message shown so we can inspect it directly for you.

Thanks & Regards,
Naman Bansod
Customer Support Specialist
🌐 Pabbly.com
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