--- title: "Sync signups to Mailchimp" description: "Add every back in stock signup to a Mailchimp audience automatically." url: https://help.stoqapp.com/back-in-stock/sync-visitors-to-mailchimp/ product: "Back in Stock" section: "Integrations / Marketing tools" last_updated: 2026-09-28 --- # Sync signups to Mailchimp > Add every back in stock signup to a Mailchimp audience automatically. STOQ can add each customer who signs up for a back in stock alert to a Mailchimp audience, as soon as they register. You pick which of your existing audiences receives them. Use this if you run campaigns from Mailchimp and want new signups added as contacts without exporting anything. ## Before you begin | Requirement | Detail | |---|---| | A paid plan | The sync toggle is disabled on the free plan. | | A Mailchimp API key | Generate one in Mailchimp and copy the whole key, including the data center suffix at the end, for example `-us21`. STOQ uses that suffix to reach your account. | | An audience in Mailchimp | Create the audience you want signups added to in Mailchimp first, then select it in STOQ during setup. | ## Get your Mailchimp API key Before you connect STOQ to Mailchimp, generate a private API key in your Mailchimp account. You'll paste it into STOQ in the next section. 1. **Log in to Mailchimp** Log in to your Mailchimp account. 2. **Open your account menu** Click your profile icon in the top-right corner. 3. **Open Account & Billing** Select **Account & Billing**. 4. **Go to API keys** Go to **Extras > API keys**. 5. **Create a new key** Click **Create New Key**. 6. **Copy the key** Copy the generated API key and keep it somewhere safe. You'll need it in the next section. [Image: The Mailchimp Account & Billing menu](https://help.stoqapp.com/images/general/api1.png) [Image: The Extras dropdown menu in Mailchimp with API keys highlighted](https://help.stoqapp.com/images/general/api2.png) [Image: Creating and copying a new Mailchimp API key](https://help.stoqapp.com/images/general/api3.png) ## Set it up On a phone, this menu is collapsed. In the **Shopify mobile app**, tap the **STOQ** logo at the top of the screen to open it, then choose the section named below. There is no hamburger icon. See [Finding the STOQ menu](https://help.stoqapp.com/general/getting-started-with-stoq/#finding-the-stoq-menu). 1. **Open the Mailchimp integration** 1. In the left menu bar of the STOQ app, click **Back in stock alerts**. 2. Click the **Settings** tab, then open the **Integrations** sub-tab. 3. Click **See integrations** to open the full **Integrations** page. 4. In the **Marketing** section, find the **Mailchimp** card and click **Set up**. [Image: The Integrations sub-tab under Back in stock alerts Settings](https://help.stoqapp.com/images/general/inter.png) [Image: The Mailchimp card in the Marketing section](https://help.stoqapp.com/images/general/mailchimp.png) 2. **Turn on the sync toggle** Enable **Sync visitors with Mailchimp**. [Image: The Sync visitors with Mailchimp setting showing Off with a Turn on button](https://help.stoqapp.com/images/general/mailon.png) 3. **Add your Mailchimp API key** Paste your key into the **Mailchimp API key** field under **API key**. Once saved, the card reads "Your Private API key is configured", with a **Change** link to update it later. If you don't have a key yet, see [Get your Mailchimp API key](#get-your-mailchimp-api-key) above. [Image: The Mailchimp API key field](https://help.stoqapp.com/images/general/key.png) 4. **Choose the audience** Under **Audience**, click **Fetch audiences**, then pick the one you want in the **Select audience** dropdown. Each option shows the audience name and its contact count. The card then reads "STOQ syncs profiles to the [name] audience/list on your Mailchimp account", with a **Change** link if you need to switch later. [Image: The Fetch audiences button in the STOQ Mailchimp panel](https://help.stoqapp.com/images/general/fetch.png) 5. **Set a profile tag (optional)** Enter a tag in the **Profile tags** field, shared with Shopify, Klaviyo, and Omnisend. [Image: The Profile tags field](https://help.stoqapp.com/images/general/tags.png) 6. **Save** Click **Save** in the save bar at the top of the page. Once connected, the card shows a **Marketing consent** summary. If you collect [marketing consent](https://help.stoqapp.com/back-in-stock/notify-me-mailing-list-optin/) on the signup form, Mailchimp treats the profile as subscribed only when the customer opted in. [Image: The Marketing consent section with the Enable consent collection button in STOQ](https://help.stoqapp.com/images/general/collection.png) ## Check your setup 1. Sign up for a restock alert yourself with a test email. See [Test back in stock alerts](https://help.stoqapp.com/back-in-stock/test-back-in-stock-alerts/). 2. Open the audience you selected in Mailchimp and confirm the test contact appears. ## Troubleshooting ### Fetch audiences returns no lists or a warning banner The banner text comes straight from Mailchimp. Check the key is correct, still valid, and includes its data center suffix, then click **Fetch audiences** again. If audiences load but yours isn't among them, it belongs to a different Mailchimp account than the key does. ### The Mailchimp toggle switched itself off STOQ turns the sync off and clears the API key and selected audience when Mailchimp rejects a request as an invalid key or as an action the key isn't permitted to take. Generate a new API key in Mailchimp, turn **Sync visitors with Mailchimp** back on, enter the key, then select the audience again. ### A signup didn't sync Confirm the toggle is on and saved, an audience is selected, and the API key still shows as configured. Signups without an email address are skipped, since Mailchimp needs one. ### The toggle is greyed out It's a paid-plan feature. Upgrade to unlock it. ## FAQ ### Does this sync my existing waitlist too? No. Only new signups sync, from the moment you turn the toggle on. Contact STOQ support to backfill existing customers. ### What happens if I don't choose an audience? STOQ falls back to the first audience in your Mailchimp account, and if the account has none, it tries to create one named "Stoq!". Mailchimp accounts that restrict who can create audiences reject that request, and signups then fail to sync, so pick an audience yourself. ### Does a customer need to opt in to marketing first? No. Every signup syncs. Consent only affects whether Mailchimp treats the profile as subscribed to campaigns. ## Related guides - [Sync signups to Omnisend](https://help.stoqapp.com/back-in-stock/sync-visitors-to-omnisend/): The same, for Omnisend. - [Sync signups to your marketing tool](https://help.stoqapp.com/back-in-stock/sync-signups-to-marketing-tools/): Overview of every sync destination. - [Let customers join your mailing list](https://help.stoqapp.com/back-in-stock/notify-me-mailing-list-optin/): Add a marketing consent checkbox to the signup form.