diff --git a/src/application/services/contact_service.rs b/src/application/services/contact_service.rs
index 3ede5ecd..395b810a 100644
--- a/src/application/services/contact_service.rs
+++ b/src/application/services/contact_service.rs
@@ -535,10 +535,16 @@ impl ContactUseCase for ContactService {
         let address_book_id = Uuid::parse_str(&dto.address_book_id)
             .map_err(|_| DomainError::validation_error("Invalid address book ID format"))?;
 
-        // Check if user has write access to the address book
+        // AuthZ audit #19 (2026-07-12): previously required
+        // `Permission::Update`, which is NOT in the Contributor bundle
+        // (Read + Create) — Contributor grantees on a shared address
+        // book couldn't add contacts via REST or CardDAV PUT despite
+        // holding the intended Create permission. `Delete` uses Delete
+        // (audit #13, above); creation must use Create. Same fix
+        // applied to `create_contact_from_vcard` + `create_group`.
         let caller_id = Uuid::parse_str(&dto.user_id)
             .map_err(|_| DomainError::validation_error("Invalid user ID format"))?;
-        self.require_address_book_perm(&address_book_id, &caller_id, Permission::Update)
+        self.require_address_book_perm(&address_book_id, &caller_id, Permission::Create)
             .await?;
 
         // Convert DTOs to domain entities
@@ -614,10 +620,13 @@ impl ContactUseCase for ContactService {
         let address_book_id = Uuid::parse_str(&dto.address_book_id)
             .map_err(|_| DomainError::validation_error("Invalid address book ID format"))?;
 
-        // Check if user has write access to the address book
+        // AuthZ audit #19 — see the sibling `create_contact` above.
+        // This is the CardDAV `PUT contact.vcf` entry point; the fix
+        // unblocks Contributor grantees creating contacts through the
+        // CardDAV protocol as well as the REST surface.
         let caller_id = Uuid::parse_str(&dto.user_id)
             .map_err(|_| DomainError::validation_error("Invalid user ID format"))?;
-        self.require_address_book_perm(&address_book_id, &caller_id, Permission::Update)
+        self.require_address_book_perm(&address_book_id, &caller_id, Permission::Create)
             .await?;
 
         // Parse vCard data
@@ -889,10 +898,10 @@ impl ContactUseCase for ContactService {
         let address_book_id = Uuid::parse_str(&dto.address_book_id)
             .map_err(|_| DomainError::validation_error("Invalid address book ID format"))?;
 
-        // Check if user has write access to the address book
+        // AuthZ audit #19 — see the sibling `create_contact` above.
         let caller_id = Uuid::parse_str(&dto.user_id)
             .map_err(|_| DomainError::validation_error("Invalid user ID format"))?;
-        self.require_address_book_perm(&address_book_id, &caller_id, Permission::Update)
+        self.require_address_book_perm(&address_book_id, &caller_id, Permission::Create)
             .await?;
 
         let group = ContactGroup::new(address_book_id, dto.name);
diff --git a/tests/api/contacts.hurl b/tests/api/contacts.hurl
index 566132ad..7057b488 100644
--- a/tests/api/contacts.hurl
+++ b/tests/api/contacts.hurl
@@ -518,6 +518,52 @@ HTTP 200
 jsonpath "$.id" == "{{audit13_contact_id}}"
 
 
+# ─────────────────────────────────────────────────────────────
+# Step 21h–21i — Regression pin for AuthZ audit #19 (2026-07-12).
+#
+# `ContactService::create_contact` + `create_contact_from_vcard`
+# + `create_group` used to `authz.require(Update)` on the address
+# book, which the Contributor bundle (Read + Create) does NOT
+# satisfy — so Contributor grantees were blocked from adding
+# contacts via REST or CardDAV PUT despite holding the intended
+# Create permission. Not a bypass, an over-restrictive gate.
+# Fix: `Permission::Create`. Sibling `#13` above closed the
+# mirror bug on the delete verbs.
+#
+# The pin demotes Bob from Editor (Step 21d) to Contributor —
+# Contributor is the minimal role that MUST succeed post-fix and
+# FAILED pre-fix. Bob then POSTs a contact via REST; pre-fix this
+# 403'd, post-fix returns 201.
+# ─────────────────────────────────────────────────────────────
+
+# 21h — Demote Bob from Editor to Contributor.
+PUT {{base_url}}/api/grants/role
+Authorization: Bearer {{token}}
+Content-Type: application/json
+{
+  "subject":  { "type": "user",         "id": "{{bob_user_id}}" },
+  "resource": { "type": "address_book", "id": "{{share_book_id}}" },
+  "role":     "contributor"
+}
+
+HTTP 200
+
+
+# 21i — Bob (Contributor) creates a contact → 201. Pre-fix, the
+# service required Update which Contributor's bundle doesn't hold,
+# so this 403'd and the CardDAV surface was equally blocked.
+POST {{base_url}}/api/address-books/{{share_book_id}}/contacts
+Authorization: Bearer {{bob_token}}
+Content-Type: application/json
+{
+  "full_name": "audit-19 contributor-can-create canary"
+}
+
+HTTP 201
+[Captures]
+audit19_contact_id: jsonpath "$.id"
+
+
 # Step 22 — Alice revokes the grant.
 DELETE {{base_url}}/api/grants/{{share_grant_id}}
 Authorization: Bearer {{token}}