diff --git a/stores/__tests__/contact-store.test.ts b/stores/__tests__/contact-store.test.ts
index 8569ef391..75fc251da 100644
--- a/stores/__tests__/contact-store.test.ts
+++ b/stores/__tests__/contact-store.test.ts
@@ -1201,6 +1201,58 @@ describe('contact-store', () => {
       );
     });
 
+    // Card ids repeat across accounts (live on 0.16 and 1.0: the sharee's own
+    // card and one it creates in the owner's shared book both got "c"). A card
+    // created in a shared book was kept under its bare id: deleting it right
+    // after deleted the own card with that id.
+    it('keeps a card created in a shared book apart from an own card with the same id', async () => {
+      useContactStore.setState({
+        addressBooks: [
+          { id: 'ab-1', name: 'Personal', isDefault: true },
+          { id: 'acct-a:ab-7', originalId: 'ab-7', name: 'Team', isShared: true, accountId: 'acct-a', accountName: 'Alice' },
+        ],
+        contacts: [makeContact({ id: 'c', addressBookIds: { 'ab-1': true } })],
+      });
+      const client = makeClient();
+      client.createContact.mockImplementation(async (c: Partial<ContactCard>) => ({ ...makeContact(), ...c, id: 'c' }));
+
+      await useContactStore.getState().createContact(
+        client as unknown as IJMAPClient,
+        { addressBookIds: { 'acct-a:ab-7': true } },
+      );
+
+      expect(client.createContact).toHaveBeenCalledWith(expect.objectContaining({ addressBookIds: { 'ab-7': true } }), 'acct-a');
+      const created = useContactStore.getState().contacts[1];
+      expect(created).toMatchObject({
+        id: 'acct-a:c', originalId: 'c', isShared: true, accountId: 'acct-a', accountName: 'Alice',
+        addressBookIds: { 'acct-a:ab-7': true },
+      });
+
+      await useContactStore.getState().deleteContact(client as unknown as IJMAPClient, 'acct-a:c');
+
+      expect(client.deleteContact).toHaveBeenCalledWith('c', 'acct-a');
+      expect(useContactStore.getState().contacts.map((c) => c.id)).toEqual(['c']);
+    });
+
+    it('namespaces a card created through another login like that login\'s listing', async () => {
+      useContactStore.setState({
+        addressBooks: [
+          { id: 'me@host::ab-1', originalId: 'ab-1', localAccountId: 'me@host', name: 'Personal', isDefault: true },
+        ],
+      });
+      const client = makeClient();
+
+      await useContactStore.getState().createContact(
+        client as unknown as IJMAPClient,
+        { addressBookIds: { 'me@host::ab-1': true } },
+      );
+
+      expect(useContactStore.getState().contacts[0]).toMatchObject({
+        id: 'me@host::created-id', originalId: 'created-id', localAccountId: 'me@host',
+        addressBookIds: { 'me@host::ab-1': true },
+      });
+    });
+
     it('moves to a namespaced personal book with the raw id and keeps the display id locally', async () => {
       const target = { id: 'me@host::ab-2', originalId: 'ab-2', localAccountId: 'me@host', name: 'Work' };
       useContactStore.setState({
diff --git a/stores/contact-store.ts b/stores/contact-store.ts
index 62b41cf2a..7171f4b7d 100644
--- a/stores/contact-store.ts
+++ b/stores/contact-store.ts
@@ -710,19 +710,31 @@ export const useContactStore = create<ContactStore>()(
             ? await writeContactWithNewPhoto(owner, accountId, cleanedContact, options.photoKey,
               (card) => owner.createContact(card, accountId))
             : await owner.createContact(cleanedContact, accountId);
-          // Preserve shared account metadata
-          if (contact.isShared && contact.accountId) {
-            created.accountId = contact.accountId;
-            created.accountName = contact.accountName;
-            created.isShared = true;
-            created.id = `${contact.accountId}:${created.id}`;
-            created.originalId = created.id.includes(':') ? created.id.split(':').slice(1).join(':') : created.id;
+          // The card under the id the listings give it (getAllContacts, then
+          // prefixContactsWithLocalAccount): card ids repeat across accounts,
+          // and one from a shared book kept under its bare id was taken for
+          // the own card of that id by the next change or delete.
+          let stored = created;
+          if (accountId) {
+            stored = {
+              ...created,
+              id: `${accountId}:${created.id}`,
+              originalId: created.id,
+              accountId,
+              accountName: contact.accountName
+                ?? get().addressBooks.find(b => b.isShared && b.accountId === accountId)?.accountName,
+              isShared: true,
+              addressBookIds: Object.fromEntries(
+                Object.entries(created.addressBookIds ?? {}).map(([bookId, v]) => [`${accountId}:${bookId}`, v]),
+              ),
+            };
           }
+          if (localAccountId) stored = prefixContactsWithLocalAccount([stored], localAccountId)[0];
           set((state) => ({
-            contacts: [...state.contacts, created],
+            contacts: [...state.contacts, stored],
             isLoading: false,
           }));
-          void contactHooks.onAfterContactCreate.emit(contactToView(created));
+          void contactHooks.onAfterContactCreate.emit(contactToView(stored));
           return true;
         } catch (error) {
           const msg = error instanceof Error ? error.message : 'Failed to create contact';