diff --git a/apps/api/src/controllers/Actions.ts b/apps/api/src/controllers/Actions.ts
index 412ba99..3e74349 100644
--- a/apps/api/src/controllers/Actions.ts
+++ b/apps/api/src/controllers/Actions.ts
@@ -72,12 +72,13 @@ export class Actions {
 
     // Create or update contact with persistent data only
     // ContactService.upsert will filter out non-persistent fields
-    // Event tracking should subscribe contacts by default
+    // Event tracking should subscribe new contacts by default (subscribed=true in ContactService)
+    // but preserve existing subscription state for existing contacts
     const contact = await ContactService.upsert(
       auth.projectId,
       email,
       data as Record<string, unknown> | undefined,
-      subscribed ?? true,
+      subscribed,
     );
 
     // Track the event with ALL data (persistent + non-persistent)
@@ -268,7 +269,9 @@ export class Actions {
 
       // Create or update contact with metadata
       // Transactional emails should not subscribe contacts by default
-      const contact = await ContactService.upsert(auth.projectId, recipient.email, recipientData, subscribed ?? false);
+      // New contacts default to unsubscribed unless explicitly opted in
+      // Existing contacts preserve their subscription state unless explicitly changed
+      const contact = await ContactService.upsert(auth.projectId, recipient.email, recipientData, subscribed, false);
 
       // Get merged data including non-persistent fields for template rendering
       const mergedData = ContactService.getMergedData(contact, data as Record<string, unknown> | undefined);
diff --git a/apps/api/src/services/ContactService.ts b/apps/api/src/services/ContactService.ts
index e7f0b1d..9c032be 100644
--- a/apps/api/src/services/ContactService.ts
+++ b/apps/api/src/services/ContactService.ts
@@ -199,6 +199,7 @@ export class ContactService {
     email: string,
     data?: Record<string, unknown>,
     subscribed?: boolean,
+    defaultSubscribed: boolean = true,
   ): Promise<Contact> {
     // Find existing contact
     const existing = await prisma.contact.findFirst({
@@ -292,7 +293,7 @@ export class ContactService {
           projectId,
           email,
           data: Object.keys(mergedData).length > 0 ? toPrismaJson(mergedData) : Prisma.JsonNull,
-          subscribed: subscribed ?? true,
+          subscribed: subscribed ?? defaultSubscribed,
         },
       });
     }