diff --git a/features/conversation-assistant/macos/Sources/Services/iMessageReader.swift b/features/conversation-assistant/macos/Sources/Services/iMessageReader.swift
index 231bf75da..6d7fb92dd 100644
--- a/features/conversation-assistant/macos/Sources/Services/iMessageReader.swift
+++ b/features/conversation-assistant/macos/Sources/Services/iMessageReader.swift
@@ -82,6 +82,7 @@ class iMessageReader {
 
             // Fetch all contacts with phone numbers and emails
             let keysToFetch: [CNKeyDescriptor] = [
+                CNContactIdentifierKey as CNKeyDescriptor,
                 CNContactGivenNameKey as CNKeyDescriptor,
                 CNContactFamilyNameKey as CNKeyDescriptor,
                 CNContactPhoneNumbersKey as CNKeyDescriptor,
@@ -96,27 +97,30 @@ class iMessageReader {
 
                 guard !fullName.isEmpty else { return }
 
-                // Index by phone numbers
-                for phone in contact.phoneNumbers {
-                    let normalized = self.normalizePhoneNumber(phone.value.stringValue)
-                    self.contactCache[normalized] = ContactInfo(
-                        identifier: normalized,
-                        displayName: fullName,
-                        phoneNumber: normalized,
-                        email: nil
-                    )
+                // Get all phones and emails for this single contact
+                let phones = contact.phoneNumbers.map { self.normalizePhoneNumber($0.value.stringValue) }
+                let emails = contact.emailAddresses.map { ($0.value as String).lowercased() }
+
+                // Create a complete ContactInfo with first phone/email (for sync)
+                let completeContact = ContactInfo(
+                    identifier: phones.first ?? emails.first ?? contact.identifier,
+                    displayName: fullName,
+                    phoneNumber: phones.first,
+                    email: emails.first
+                )
+
+                // Index by all phones (all point to same complete contact)
+                for phone in phones {
+                    self.contactCache[phone] = completeContact
                 }
 
-                // Index by emails
-                for email in contact.emailAddresses {
-                    let emailStr = email.value as String
-                    self.contactCache[emailStr.lowercased()] = ContactInfo(
-                        identifier: emailStr,
-                        displayName: fullName,
-                        phoneNumber: nil,
-                        email: emailStr
-                    )
+                // Index by all emails (all point to same complete contact)
+                for email in emails {
+                    self.contactCache[email] = completeContact
                 }
+
+                // Also index by contact identifier for direct lookup
+                self.contactCache[contact.identifier] = completeContact
             }
 
             NSLog("iMessageReader: Loaded \(contactCache.count) contact entries")
@@ -140,12 +144,14 @@ class iMessageReader {
     }
 
     /// Get all cached contacts for syncing
+    /// Each CNContact from address book is already a single person - deduplicate by identifier
     func getAllContacts() -> [ContactInfo] {
-        // Deduplicate by display name (same person may have multiple phones/emails)
+        // Deduplicate by identifier (unique per CNContact, not by name)
+        // This prevents merging two different "John Smith" contacts
         var seen = Set<String>()
         return contactCache.values.filter { contact in
-            if seen.contains(contact.displayName) { return false }
-            seen.insert(contact.displayName)
+            if seen.contains(contact.identifier) { return false }
+            seen.insert(contact.identifier)
             return true
         }
     }