My subscribers aren't syncing to Klaviyo or Mailchimp

If visitors are signing up through your popup but their information isn't appearing in Klaviyo or Mailchimp, work through these checks in order.

1. Make sure you're on a paid plan

Klaviyo, Mailchimp, and all other premium integrations are only available on paid plans (Launch and above). If you're on the Always Free plan, subscribers sync to Shopify Customers only.

Check your current plan in Settings → Plans and billing.

2. Check that the integration is connected

1. Go to your campaign in the 1ClickPopup app
2. Open the Settings tab
3. Scroll to the Integrations section
4. Make sure Klaviyo or Mailchimp is added and showing as connected

If the integration isn't listed, click to add it and complete the setup (you'll need your API key from Klaviyo or Mailchimp).

3. Check your API key

An expired, revoked, or incorrectly copied API key will silently prevent syncing.

For Klaviyo:

1. Log in to your Klaviyo account
2. Go to Settings → API Keys
3. Confirm the key you entered in 1ClickPopup is still active
4. Make sure the key has all permissions
5. If you're unsure, generate a new key with the correct permissions and update it in 1ClickPopup

For Mailchimp:

1. Log in to your Mailchimp account
2. Go to Profile → Extras → API Keys
3. Confirm the key is still active
4. If you're unsure, generate a new key and update it in 1ClickPopup

4. Check if double opt-in is enabled

If you have double opt-in turned on, subscribers won't sync until they click the confirmation link in the email sent by 1ClickPopup.

1. Open your campaign's Settings tab
2. Check the Opt-in method - if it's set to "Double opt-in," the subscriber only syncs after confirmation
3. Ask your test subscriber to check their inbox (and spam folder) for the confirmation email

If you're testing, make sure you clicked the confirmation link yourself before checking Klaviyo or Mailchimp.

5. Check the right list or audience

For Klaviyo: Subscribers sync to a Klaviyo list. Make sure you're checking the correct list in your Klaviyo account - not just the "All Profiles" view but the specific list linked to your campaign.

For Mailchimp: Subscribers sync to a specific Mailchimp audience. Confirm you're checking the audience that's connected to your 1ClickPopup campaign.

6. Test with a new signup

Previous test signups may have been blocked by duplicate prevention. To test a clean sync:

1. Open your store in an incognito/private browser window
2. Sign up with an email address you haven't used before
3. If double opt-in is on, click the confirmation link
4. Wait a few minutes, then check Klaviyo or Mailchimp for the new subscriber

If the new subscriber appears, syncing is working - your earlier test subscribers were likely blocked as duplicates.

7. Subscribers are syncing to Shopify but not Klaviyo/Mailchimp

If subscribers appear in Shopify Customers but not in Klaviyo or Mailchimp, the issue is with the integration connection - not with the popup itself. Go back to steps 2 and 3 and double-check your integration setup and API key.

Still not working?

Contact us through the chat widget and include:

• Your campaign name
• Which integration isn't syncing (Klaviyo, Mailchimp, or both)
• Whether subscribers are appearing in Shopify Customers
• Whether double opt-in is enabled

We'll take a look and get it sorted.