Automate Mailchimp Contact Creation from Squarespace via n8n

1. The Real-World Problem: Managing Squarespace Newsletter Signups Manually

Meet Sarah, the marketing manager at a mid-sized e-commerce brand using Squarespace for their website and newsletter form. Sarah faces a common pain point: every day, new newsletter signups land in a Google Sheets spreadsheet because Squarespace doesn’t directly sync with Mailchimp for active audiences—only for empty new audiences. This means she has to manually add those contacts into Mailchimp to start sending them promotional emails.

Sarah spends at least 2 hours daily cross-checking Sheets and Mailchimp, risking errors like duplicate contacts or missing entries due to manual copy-pasting. This leads to lost marketing opportunities and inconsistent communication with potential customers. As her subscriber base grows, the risk and effort increase dramatically.

This workflow uniquely solves Sarah’s problem by automating the entire process. Instead of manually updating Mailchimp, new subscribers are automatically added to the correct Mailchimp audience directly from the Google Sheets that captures Squarespace newsletter signup data.

2. What This Automation Does

When you run this n8n workflow, it:

• Fetches new newsletter submissions from a Google Sheets spreadsheet that logs Squarespace form signups.
• Processes each subscriber one by one, ensuring no overload on Mailchimp’s API.
• Creates or updates a Mailchimp contact in the specified audience with the subscriber’s email and name.
• Maintains subscriber sign-up date timestamp for accurate audience records.
• Allows for manual triggering or scheduled periodic runs to keep your mailing list up to date.
• Logs errors without stopping the entire workflow, ensuring continuous operation.

With this automation, Sarah now saves over 14 hours a week she used to spend manually managing contacts, while ensuring every new signup is accounted for with zero manual errors.

3. Prerequisites ⚙️

• n8n account (cloud or self-hosted) 🔌
• Google Sheets account with the Squarespace newsletter spreadsheet 📊
• Mailchimp account with an audience set up to receive contacts 📧
• Google Sheets OAuth2 credentials configured in n8n 🔑
• Mailchimp API credentials configured in n8n 🔑

4. Step-by-Step Guide to Setup and Understand This Workflow

Step 1: Prepare Your Squarespace Newsletter Spreadsheet in Google Sheets

First, make sure you have a spreadsheet with columns that capture at least the following from your Squarespace form submissions:

• Submitted On (Date/time of signup)
• Email Address
• Name

Use the sample provided in the workflow notes for format guidance or clone it here: Sample Sheet.

Check that the sheet ID and name match what you will enter in the Google Sheets node.

Common Mistake: Not sharing the sheet with the Google account connected to n8n can cause authentication errors.

Step 2: Configure the Google Sheets Node

In n8n, add (or locate) the Squarespace newsletter submissions node of type Google Sheets. Set:

• Document ID: The Google Sheet ID (found in the URL after /d/)
• Sheet Name: Usually “Sheet1” or “gid=0” as per your sheet’s tab
• Credentials: Select your Google Sheets OAuth2 API credential.

This node fetches all rows (newsletter signups) from your spreadsheet.

Expected Outcome: When clicked “Execute Node,” you should see all submission rows listed.

Common Mistake: Using the wrong sheet ID or name causes an empty output.

Step 3: Understand the SplitInBatches Node for Processing Each Signup

The workflow uses a node named Loop Over each item of type SplitInBatches that processes each subscriber row individually. This prevents hitting Mailchimp’s rate limits by sending subscribers in manageable batches (default size 1).

This is critical for large lists and to reduce API errors.

Step 4: Configure the Mailchimp Node to Add Contacts

The last step is the Add new member to Mailchimp node (of type Mailchimp), which:

• Expects subscriber data fields from the batch input
• Uses the email from the spreadsheet’s Email Address field
• Sets subscription status to subscribed
• Passes the subscriber’s sign-up date as a timestamp for accurate record-keeping
• Maps the subscriber’s first name to the Mailchimp merge field FNAME

Here, you must select or create API credentials for Mailchimp in n8n.

Common Mistake: Incorrect merge field names cause failures — double-check your Mailchimp audience settings.

Step 5: Triggering the Workflow

You can trigger this workflow manually using the Manual Trigger node or set the Schedule Trigger to run automatically once or periodically (e.g., daily or hourly).

Check the Schedule Trigger’s interval settings to match your needs.

Step 6: Running a Workflow Test

Click Execute Workflow in n8n. Watch the execution logs to ensure each subscriber is processed and added to Mailchimp without errors.

Success means: No error, and your Mailchimp audience shows new contacts matching the spreadsheet entries.

Step 7: Review Workflow Error Handling

The Mailchimp node has an error continuation setting enabled, so if some subscribers cause errors (e.g., already subscribed emails), the workflow continues processing the next items. This ensures the workflow doesn’t stop midway.

5. Customizations ✏️

• Change Subscriber Fields Mapped: Adjust the mergeFieldsValues array in the Mailchimp node to include last name, phone, or other custom audience fields if needed.
• Batch Size Tuning: In the Loop Over each item SplitInBatches node, change the batch size to process multiple subscribers per API call if your Mailchimp plan permits.
• Modify Schedule Trigger: Adjust the interval (hourly, daily) or add multiple schedule triggers to run at different times.
• Add Email Validation Node: Insert an additional node before Mailchimp to validate email format or check for unsubscribed status.

6. Troubleshooting 🔧

Problem: “Google Sheets node returns empty data or authentication failed”
Cause: Google Sheets credentials missing or permission error.
Solution: Go to Credentials in n8n and re-authenticate your Google Sheets account. Make sure your sheet is shared with this user.

Problem: “Mailchimp node fails with 400 or merge field error”
Cause: Incorrect merge field names or invalid emails.
Solution: Double-check your Mailchimp audience merge fields match exactly what you use in the node, and validate emails before sending.

Problem: “Workflow stops unexpectedly on subscriber errors”
Cause: Error continuation not enabled.
Solution: In the Mailchimp node, set ‘On Error’ to ‘Continue’ to prevent stoppage.

7. Pre-Production Checklist ✅

• Verify Google Sheets document ID and sheet name are exact.
• Test Google Sheets node to confirm data pulls correctly.
• Check Mailchimp credentials and audience field mapping.
• Validate subscriber data format (email, dates, names).
• Run test executions via manual trigger and check contacts added in Mailchimp.
• Ensure error continuation setting prevents workflow stop on invalid entries.
• Backup your spreadsheet data before starting live runs.

8. Deployment Guide

Activate the workflow in n8n by enabling it after testing. Choose the schedule trigger interval to match your newsletter signup frequency—commonly daily or hourly.

Monitor run status and execution logs regularly inside n8n to ensure smooth operation. Adjust batch sizes or error handling if scaling up subscriber counts.

9. FAQs

• Can I use Airtable instead of Google Sheets?
  Yes, but you need to replace the Google Sheets node with Airtable node configured for your base and table.
• Does this consume Mailchimp API credits?
  Mailchimp has generous API limits per account which this workflow respects by batch processing.
• Is my subscriber data secure?
  All data flows stay within your n8n instance and API credentials are securely stored.
• Can I scale for 10,000+ subscribers?
  Yes, adjust the batch size and schedule frequency to ensure stable API usage.

10. Conclusion

By following this guide, you’ve automated the tedious task of syncing Squarespace newsletter signups to Mailchimp audiences using n8n. This workflow saves countless hours and avoids manual errors, ensuring timely marketing communication with new subscribers.

Next, consider adding email validation, segment creation, or automated welcome emails in Mailchimp triggered by new contacts for further streamlining your marketing.

Embrace the power of automation and keep your subscriber list fresh without lifting a finger!