Sync STOQ customer data to Mailchimp for email marketing

STOQ can automatically sync customer data to Mailchimp whenever a visitor signs up for a back-in-stock or preorder alert on your store. Each synced customer is added to a dedicated Mailchimp list with a tag and their marketing consent status, so you can include them in your email campaigns right away. This guide walks you through connecting your Mailchimp account and enabling the sync.

Before You Begin

Make sure you have the following before you enable the Mailchimp integration:

• A paid STOQ plan (the Mailchimp sync is not available on the free plan)
• A Mailchimp account with permission to create API keys
• STOQ installed and active on your Shopify store

How to Get Your Mailchimp API Key

Before you can connect STOQ to Mailchimp, you need to generate a Private API key in your Mailchimp account.

1. Log in to your Mailchimp account.
2. Click your profile icon in the top-right corner.
3. Select Account & Billing.
4. Navigate to Extras > API keys.
5. Click Create New Key.
6. Copy the generated API key and keep it somewhere safe. You will need it in the next section.

How to Connect Mailchimp and Enable Customer Sync

Follow these steps to connect your Mailchimp account and start syncing customers.

Step 1: Open the Integrations Page

1. Open the STOQ app in your Shopify admin.
2. Click Back in stock alerts in the left-hand menu.
3. Navigate to the Settings section, then scroll to Integrations.
4. Click Set up on the Mailchimp card.

Step 2: Enable the Sync Toggle

1. Turn on the Sync visitors with Mailchimp toggle.
2. Click Save in the top bar to confirm.

Step 3: Enter Your Mailchimp API Key

1. After enabling the toggle, a Mailchimp API key field appears.
2. Paste the API key you copied from your Mailchimp account.
3. Click Save.

Once saved, STOQ validates the key and connects to your Mailchimp account. A green checkmark and "Your Private API key is configured" message confirm the connection.

Step 4: Set Your Profile Tag

1. In the Settings section beneath the toggle, locate the Profile tags field.
2. Enter a tag value (for example, restock-rocket or back-in-stock-signup).
3. Click Save.

STOQ adds this tag to every customer it syncs to Mailchimp. The default value is restock-rocket.

What STOQ Syncs to Mailchimp

STOQ sends detailed customer information to your Mailchimp list so you can segment and target your campaigns.

Customer Details

When a customer signs up for an alert, STOQ adds them to your Mailchimp list with:

• Email address (required — customers without an email are not synced)
• First name (FNAME merge field)
• Last name (LNAME merge field)
• Phone number (PHONE merge field, if provided)
• Tag (your profile tag value, default: restock-rocket)

Marketing Consent

STOQ sets the subscription status based on the customer's marketing preference:

• Accepts marketing: Added as subscribed — they will receive your Mailchimp campaigns.
• Does not accept marketing: Added as unsubscribed — their profile is stored but they will not receive campaigns.

Automatic List Creation

The first time STOQ syncs a customer to Mailchimp, it checks whether a list already exists in your account.

• If no list exists: STOQ automatically creates a new Mailchimp list named "Stoq!". The list is configured with your store's details (domain, address, city, and country).
• If a list already exists: STOQ continues adding customers to the same list.

You do not need to create a list manually. STOQ handles this for you.

Known Limitations

There are a few constraints to keep in mind when using the Mailchimp sync.

• The Mailchimp integration requires a paid STOQ plan. Free-plan stores cannot enable it.
• Email is required. Customers who sign up with only a phone number or push notifications are not synced to Mailchimp.
• STOQ syncs customers one at a time as they sign up. There is no bulk retroactive sync for customers who signed up before you enabled the integration.
• The profile tag field is shared across all marketing integrations. You cannot set a different tag for Mailchimp and Shopify independently.
• If the Mailchimp API key becomes invalid or permissions are revoked, STOQ automatically disables the integration and clears the API key. You will need to re-enter a valid key to resume syncing.
• STOQ creates new list members each time. If a customer with the same email already exists on the list, Mailchimp may return an error for that sync attempt.

Troubleshooting

If customers are not syncing to Mailchimp as expected, check the table below.

FAQs

Q. Where do I find my Mailchimp API key?

A. Log in to Mailchimp, click your profile icon, go to Account & Billing > Extras > API keys, and click Create New Key. Copy the full key including the data center suffix.

Q. Does STOQ create a Mailchimp list automatically?

A. Yes. The first time a customer is synced, STOQ creates a list named "Stoq!" in your Mailchimp account if one does not already exist. All future customers are added to this same list.

Q. Can I sync customers who signed up before I enabled the integration?

A. No. STOQ only syncs customers going forward from the moment you enable the integration. Previously signed-up customers are not retroactively synced to Mailchimp.

Q. Will disabling the sync toggle remove customers from Mailchimp?

A. No. Turning off the toggle only stops new customers from being synced. Customers already in your Mailchimp list remain untouched.

Q. Why was my Mailchimp integration automatically disabled?

A. STOQ disables the integration if it detects that the API key is invalid or your Mailchimp account permissions have changed. Generate a new API key in Mailchimp, re-enable the toggle in STOQ, and enter the new key.

Q. Can I sync phone-only customers to Mailchimp?

A. No. Mailchimp requires an email address for each contact. Customers who sign up with only a phone number or push notifications are not synced.

Updated on: 09/04/2026