diff --git a/omni_chat/src/worker.ts b/omni_chat/src/worker.ts
index 6769914..795e232 100644
--- a/omni_chat/src/worker.ts
+++ b/omni_chat/src/worker.ts
@@ -212,19 +212,12 @@ function buildContactProfile(
   normalized: OmniInboundEnvelopeV1["payloadNormalized"],
   externalContactId: string,
 ): ContactProfile {
-  const firstName =
-    asString(normalized.contactFirstName) ??
-    asString(normalized.fromFirstName) ??
-    asString(normalized.chatFirstName);
-  const lastName =
-    asString(normalized.contactLastName) ??
-    asString(normalized.fromLastName) ??
-    asString(normalized.chatLastName);
-  const username =
-    asString(normalized.contactUsername) ??
-    asString(normalized.fromUsername) ??
-    asString(normalized.chatUsername);
-  const title = asString(normalized.contactTitle) ?? asString(normalized.chatTitle);
+  // Use only normalized contact-* fields (counterparty), avoid sender/chat fallbacks
+  // to prevent accidental renames to the business owner name on OUT events.
+  const firstName = asString(normalized.contactFirstName);
+  const lastName = asString(normalized.contactLastName);
+  const username = asString(normalized.contactUsername);
+  const title = asString(normalized.contactTitle);
 
   const fullName = [firstName, lastName].filter(Boolean).join(" ");
   const displayName =
diff --git a/omni_inbound/src/telegram.ts b/omni_inbound/src/telegram.ts
index 834c8b1..4b8b0d3 100644
--- a/omni_inbound/src/telegram.ts
+++ b/omni_inbound/src/telegram.ts
@@ -60,6 +60,12 @@ function normalizeNumber(value: unknown) {
   return null;
 }
 
+function normalizeId(value: unknown) {
+  if (value == null) return null;
+  const text = String(value).trim();
+  return text || null;
+}
+
 type TelegramMediaInfo = {
   kind: "voice" | "audio" | "video_note" | null;
   fileId: string | null;
@@ -159,8 +165,26 @@ export function parseTelegramBusinessUpdate(raw: unknown): OmniInboundEnvelopeV1
   const chat = asObject(message.chat);
   const from = asObject(message.from);
   const direction = detectDirection(message, chat, from);
-  const contactSource = direction === "OUT" && Object.keys(chat).length > 0 ? chat : from;
-  const fallbackContactSource = direction === "OUT" ? from : chat;
+  const ownerChatId = normalizeId(businessConnection.user_chat_id);
+  const chatId = normalizeId(chat.id);
+  const fromId = normalizeId(from.id);
+
+  let contactSource: JsonObject | null = null;
+  if (ownerChatId) {
+    // Prefer the counterparty id/source (different from connected owner chat id).
+    if (chatId && chatId !== ownerChatId) contactSource = chat;
+    if (fromId && fromId !== ownerChatId) {
+      if (!contactSource || direction === "IN") {
+        contactSource = from;
+      }
+    }
+  }
+
+  if (!contactSource) {
+    contactSource = direction === "OUT" && Object.keys(chat).length > 0 ? chat : from;
+  }
+
+  const fallbackContactSource = contactSource === chat ? from : chat;
 
   const threadExternalId =
     chat.id != null
@@ -170,11 +194,9 @@ export function parseTelegramBusinessUpdate(raw: unknown): OmniInboundEnvelopeV1
         : null;
 
   const contactExternalId =
-    contactSource.id != null
-      ? String(contactSource.id)
-      : fallbackContactSource.id != null
-        ? String(fallbackContactSource.id)
-        : null;
+    normalizeId(contactSource?.id) ??
+    normalizeId(fallbackContactSource?.id) ??
+    null;
 
   const media = pickTelegramMedia(message);
   const text =