diff --git a/src/screens/ContactDetailScreen.tsx b/src/screens/ContactDetailScreen.tsx
index 6c239b01..7e0e1e7a 100644
--- a/src/screens/ContactDetailScreen.tsx
+++ b/src/screens/ContactDetailScreen.tsx
@@ -12,7 +12,7 @@ import {
   ArrowLeft, Pencil, Trash2, Mail, Phone, MessageSquare, Share2, MapPin,
   Building, Cake, Heart, Globe, Tag, Users, FileText, BookUser,
   Copy, MoreHorizontal, Calendar as CalendarIcon, UserCircle, Languages,
-  Clock, KeyRound, FolderInput,
+  Clock, KeyRound, FolderInput, Plus,
 } from 'lucide-react-native';
 import type { RootStackParamList } from '../navigation/types';
 import type { ContactCard } from '../api/types';
@@ -86,10 +86,13 @@ export default function ContactDetailScreen() {
   const deleteContact = useContactsStore((s) => s.deleteContact);
   const createContact = useContactsStore((s) => s.createContact);
   const moveContactsToAddressBook = useContactsStore((s) => s.moveContactsToAddressBook);
+  const addContactsToGroup = useContactsStore((s) => s.addContactsToGroup);
+  const groups = React.useMemo(() => allContacts.filter(isGroup), [allContacts]);
 
   const [confirmDelete, setConfirmDelete] = React.useState(false);
   const [moreOpen, setMoreOpen] = React.useState(false);
   const [moveOpen, setMoveOpen] = React.useState(false);
+  const [groupPickerOpen, setGroupPickerOpen] = React.useState(false);
 
   if (!contact) {
     return (
@@ -108,7 +111,9 @@ export default function ContactDetailScreen() {
   }
 
   const name = getContactDisplayName(contact) || 'Unnamed';
-  const nickname = getPrimaryNickname(contact);
+  const nickname = contact.nicknames
+    ? Object.values(contact.nicknames).map((n) => n.name).filter(Boolean).join(', ')
+    : getPrimaryNickname(contact);
   const email = getContactPrimaryEmail(contact);
   const phone = contact.phones ? Object.values(contact.phones)[0]?.number : '';
   const photoUri = getContactPhotoUri(contact);
@@ -133,7 +138,8 @@ export default function ContactDetailScreen() {
   const bookNames = bookIds
     .map((id) => addressBooks.find((b) => b.id === id)?.name)
     .filter(Boolean) as string[];
-  const subtitleParts = [jobTitles[0]?.name, org].filter(Boolean) as string[];
+  // On an organization card the org name is already the heading; don't repeat it.
+  const subtitleParts = [jobTitles[0]?.name, org === name ? undefined : org].filter(Boolean) as string[];
   const hasGender = !!(contact.speakToAs && (contact.speakToAs.grammaticalGender || contact.speakToAs.pronouns));
   const firstPronoun = contact.speakToAs?.pronouns
     ? Object.values(contact.speakToAs.pronouns)[0]?.pronouns
@@ -213,8 +219,15 @@ export default function ContactDetailScreen() {
       Alert.alert('No address book', 'Cannot duplicate without an address book.');
       return;
     }
+    // Drop the UID too: the copy gets a fresh one on create, otherwise group
+    // membership by uid matches both cards and CardDAV sees two cards with one UID.
     const {
       id: _id,
+      uid: _uid,
+      originalId: _originalId,
+      accountId: _accountId,
+      accountName: _accountName,
+      isShared: _isShared,
       addressBookIds: _abIds,
       created: _created,
       updated: _updated,
@@ -250,6 +263,11 @@ export default function ContactDetailScreen() {
       label: 'Duplicate',
       onPress: () => { void doDuplicate(); },
     },
+    !isGroup(contact) && {
+      icon: <Users size={16} color={c.text} />,
+      label: 'Add to group',
+      onPress: () => setGroupPickerOpen(true),
+    },
     addressBooks.length > 0 && {
       icon: <FolderInput size={16} color={c.text} />,
       label: 'Move to address book',
@@ -632,6 +650,28 @@ export default function ContactDetailScreen() {
         onClose={() => setMoreOpen(false)}
       />
 
+      <MoreActionsSheet
+        visible={groupPickerOpen}
+        onClose={() => setGroupPickerOpen(false)}
+        items={[
+          ...groups.map((g): MoreItem => ({
+            icon: <Users size={16} color={c.text} />,
+            label: getContactDisplayName(g) || 'Group',
+            onPress: () => {
+              addContactsToGroup(g.id, [contact.id]).catch((err) => {
+                Alert.alert('Add to group failed', err instanceof Error ? err.message : 'Unknown error');
+              });
+            },
+          })),
+          ...(groups.length > 0 ? [{ separator: true } as MoreItem] : []),
+          {
+            icon: <Plus size={16} color={c.text} />,
+            label: 'New group…',
+            onPress: () => navigation.navigate('ContactForm', { asGroup: true, memberIds: [contact.id] }),
+          },
+        ]}
+      />
+
       <AddressBookPickerSheet
         visible={moveOpen}
         onClose={() => setMoveOpen(false)}
diff --git a/src/screens/GroupDetailScreen.tsx b/src/screens/GroupDetailScreen.tsx
index a39a940e..a5cecbb5 100644
--- a/src/screens/GroupDetailScreen.tsx
+++ b/src/screens/GroupDetailScreen.tsx
@@ -38,6 +38,8 @@ export default function GroupDetailScreen() {
   const allContacts = useContactsStore((s) => s.contacts);
   const updateContact = useContactsStore((s) => s.updateContact);
   const deleteContact = useContactsStore((s) => s.deleteContact);
+  const addContactsToGroup = useContactsStore((s) => s.addContactsToGroup);
+  const getGroupRecipients = useContactsStore((s) => s.getGroupRecipients);
   const group = React.useMemo(
     () => allContacts.find((c) => c.id === groupId),
     [allContacts, groupId],
@@ -70,12 +72,8 @@ export default function GroupDetailScreen() {
   const name = getContactDisplayName(group) || 'Group';
 
   const emailAll = () => {
-    const recipients: EmailAddress[] = [];
-    for (const m of members) {
-      const email = getContactPrimaryEmail(m);
-      if (!email) continue;
-      recipients.push({ name: getContactDisplayName(m) || '', email });
-    }
+    // One recipient per address: two members sharing a mailbox are sent once.
+    const recipients: EmailAddress[] = getGroupRecipients(group.id);
     if (recipients.length === 0) {
       Alert.alert('No emails', 'None of the members have an email address.');
       return;
@@ -84,14 +82,8 @@ export default function GroupDetailScreen() {
   };
 
   const addMembers = async (ids: string[]) => {
-    const existing = group.members ? { ...group.members } : {};
-    for (const id of ids) {
-      const contact = allContacts.find((c) => c.id === id);
-      const key = contact?.uid || id;
-      existing[key] = true;
-    }
     try {
-      await updateContact(group.id, { members: existing });
+      await addContactsToGroup(group.id, ids);
     } catch (err) {
       Alert.alert('Failed to add members', err instanceof Error ? err.message : 'Unknown error');
     }