diff --git a/apps/web/app/(app)/[emailAccountId]/assistant/settings/ReferralSignatureSetting.tsx b/apps/web/app/(app)/[emailAccountId]/assistant/settings/ReferralSignatureSetting.tsx
index c6b3c6f011..e405f671ac 100644
--- a/apps/web/app/(app)/[emailAccountId]/assistant/settings/ReferralSignatureSetting.tsx
+++ b/apps/web/app/(app)/[emailAccountId]/assistant/settings/ReferralSignatureSetting.tsx
@@ -10,6 +10,7 @@ import { SettingCard } from "@/components/SettingCard";
 import { useEmailAccountFull } from "@/hooks/useEmailAccountFull";
 import { useAction } from "next-safe-action/hooks";
 import { updateReferralSignatureAction } from "@/utils/actions/email-account";
+import { env } from "@/env";
 
 export function ReferralSignatureSetting() {
   const { data, isLoading, error, mutate } = useEmailAccountFull();
@@ -43,6 +44,10 @@ export function ReferralSignatureSetting() {
     [execute],
   );
 
+  if (env.NEXT_PUBLIC_DISABLE_REFERRAL_SIGNATURE) {
+    return null;
+  }
+
   return (
     <SettingCard
       title="Include referral signature"
diff --git a/apps/web/env.ts b/apps/web/env.ts
index 2ec3c70df9..3d8615d9c9 100644
--- a/apps/web/env.ts
+++ b/apps/web/env.ts
@@ -178,6 +178,10 @@ export const env = createEnv({
     NEXT_PUBLIC_OLLAMA_MODEL: z.string().optional(),
     NEXT_PUBLIC_APP_HOME_PATH: z.string().default("/setup"),
     NEXT_PUBLIC_DUB_REFER_DOMAIN: z.string().optional(),
+    NEXT_PUBLIC_DISABLE_REFERRAL_SIGNATURE: z.coerce
+      .boolean()
+      .optional()
+      .default(false),
   },
   // For Next.js >= 13.4.4, you only need to destructure client variables:
   experimental__runtimeEnv: {
@@ -232,5 +236,7 @@ export const env = createEnv({
     NEXT_PUBLIC_OLLAMA_MODEL: process.env.NEXT_PUBLIC_OLLAMA_MODEL,
     NEXT_PUBLIC_APP_HOME_PATH: process.env.NEXT_PUBLIC_APP_HOME_PATH,
     NEXT_PUBLIC_DUB_REFER_DOMAIN: process.env.NEXT_PUBLIC_DUB_REFER_DOMAIN,
+    NEXT_PUBLIC_DISABLE_REFERRAL_SIGNATURE:
+      process.env.NEXT_PUBLIC_DISABLE_REFERRAL_SIGNATURE,
   },
 });
diff --git a/apps/web/prisma/migrations/20250916133642_default_signature_enabled/migration.sql b/apps/web/prisma/migrations/20250916133642_default_signature_enabled/migration.sql
new file mode 100644
index 0000000000..e96999582e
--- /dev/null
+++ b/apps/web/prisma/migrations/20250916133642_default_signature_enabled/migration.sql
@@ -0,0 +1,2 @@
+-- AlterTable
+ALTER TABLE "public"."EmailAccount" ALTER COLUMN "includeReferralSignature" SET DEFAULT true;
diff --git a/apps/web/prisma/schema.prisma b/apps/web/prisma/schema.prisma
index e82bb65752..e246ab0167 100644
--- a/apps/web/prisma/schema.prisma
+++ b/apps/web/prisma/schema.prisma
@@ -115,7 +115,7 @@ model EmailAccount {
   about                     String?
   writingStyle              String?
   signature                 String?
-  includeReferralSignature  Boolean   @default(false)
+  includeReferralSignature  Boolean   @default(true)
   watchEmailsExpirationDate DateTime?
   watchEmailsSubscriptionId String? // For Outlook subscription ID
   lastSyncedHistoryId       String?
diff --git a/apps/web/utils/reply-tracker/generate-draft.ts b/apps/web/utils/reply-tracker/generate-draft.ts
index bab75e3d92..c13bdcb0cb 100644
--- a/apps/web/utils/reply-tracker/generate-draft.ts
+++ b/apps/web/utils/reply-tracker/generate-draft.ts
@@ -14,6 +14,7 @@ import type { EmailProvider } from "@/utils/email/types";
 import { aiCollectReplyContext } from "@/utils/ai/reply/reply-context-collector";
 import { getOrCreateReferralCode } from "@/utils/referral/referral-code";
 import { generateReferralLink } from "@/utils/referral/referral-link";
+import { env } from "@/env";
 
 const logger = createScopedLogger("generate-reply");
 
@@ -79,10 +80,12 @@ export async function fetchMessagesAndGenerateDraft(
   }
 
   const emailAccountWithIncludeReferralSignature =
-    await prisma.emailAccount.findUnique({
-      where: { id: emailAccount.id },
-      select: { includeReferralSignature: true },
-    });
+    env.NEXT_PUBLIC_DISABLE_REFERRAL_SIGNATURE
+      ? null
+      : await prisma.emailAccount.findUnique({
+          where: { id: emailAccount.id },
+          select: { includeReferralSignature: true },
+        });
 
   if (emailAccountWithIncludeReferralSignature?.includeReferralSignature) {
     const referralSignature = await getOrCreateReferralCode(