How to Send Form Submissions to ActiveCampaign (2026)

Why route ActiveCampaign signups through your own form

ActiveCampaign is a powerful automation platform, and its forms are serviceable — but they're bound to its styling and script, and the richer form features live on higher plans. For a high-conversion landing page you usually want a custom, fast form that's yours.

Own the HTML and route it through splitforms: a fully custom form with an AI spam classifier, email notifications, and a submission dashboard — while ActiveCampaign stays your automation engine. A small proxy syncs the contact, adds it to a list, and (optionally) applies a tag to trigger an automation.

Step 1 — Get your API URL, key, and list ID

In ActiveCampaign open Settings → Developer and copy your API URL (e.g. https://youraccount.api-us1.com) and API Key. Find the target list ID under Lists (shown in the URL when you open a list). Store all three as environment variables on your proxy — never in the browser.

Step 2 — The splitforms → ActiveCampaign proxy

splitforms fires a signed webhook; the proxy syncs the contact, then adds it to a list. Cloudflare Worker version:

export default {
  async fetch(req, env) {
    if (req.method !== "POST") return new Response("Method Not Allowed", { status: 405 });

    // 1. (Recommended) verify the splitforms HMAC signature header here.

    const submission = await req.json();
    const f = submission.data ?? submission;
    if (!f.email) return new Response("no email", { status: 400 });

    const base = env.AC_API_URL;            // https://youraccount.api-us1.com
    const headers = {
      "Api-Token": env.AC_API_KEY,
      "Content-Type": "application/json",
    };

    // 2. Sync (upsert) the contact by email
    const sync = await fetch(`${base}/api/3/contact/sync`, {
      method: "POST",
      headers,
      body: JSON.stringify({
        contact: {
          email: f.email,
          firstName: (f.name ?? "").split(" ")[0],
          lastName:  (f.name ?? "").split(" ").slice(1).join(" "),
          phone: f.phone,
        },
      }),
    }).then((r) => r.json());

    const contactId = sync.contact?.id;
    if (!contactId) return new Response("sync failed", { status: 502 });

    // 3. Add the contact to a list (status 1 = subscribed)
    await fetch(`${base}/api/3/contactLists`, {
      method: "POST",
      headers,
      body: JSON.stringify({
        contactList: { list: Number(env.AC_LIST_ID), contact: contactId, status: 1 },
      }),
    });

    return new Response("ok", { status: 200 });
  },
};

Deploy the Worker and paste its URL into your form's webhook settings in the splitforms dashboard. To kick off a specific automation, add a POST /api/3/contactTags call applying a tag the automation triggers on. Verify the webhook signature — see send form data to a webhook.

Step 3 — The form

Your public form only talks to splitforms with the public access key. Swap YOUR_ACCESS_KEY for the one from your free account.

<form action="https://splitforms.com/api/submit" method="POST">
  <input type="hidden" name="access_key" value="YOUR_ACCESS_KEY" />
  <input name="name" placeholder="Name" />
  <input name="email" type="email" required placeholder="Email" />
  <input name="phone" type="tel" placeholder="Phone (optional)" />

  <label><input type="checkbox" name="consent" required /> Keep me in the loop</label>

  <!-- honeypot -->
  <input type="checkbox" name="botcheck" style="display:none" tabindex="-1" autocomplete="off" />
  <button type="submit">Subscribe</button>
</form>

What to do next

• Other email tools: Kit (ConvertKit) · Brevo · Mailchimp
• CRMs: Salesforce · Pipedrive
• Webhook fundamentals: send form data to a webhook
• Ready to set it up: get a free access key

FAQ