diff --git a/.env.example b/.env.example
index db033e9..f97aec9 100644
--- a/.env.example
+++ b/.env.example
@@ -14,3 +14,4 @@ SMTP_SECURE=false
 SMTP_USER=
 SMTP_PASS=
 SMTP_FROM=
+AUTH_LOGIN_CODE_DELIVERY=email
diff --git a/src/resolvers.js b/src/resolvers.js
index 2d9c5be..19868e7 100644
--- a/src/resolvers.js
+++ b/src/resolvers.js
@@ -30,6 +30,16 @@ import { fetchTelegramConnectionProfile } from './telegram.js';
 
 const ACTIVE_ORDER_STATUSES = ['NEW', 'MANAGER_PROCESSING', 'WAITING_DOUBLE_CONFIRM', 'CONFIRMED', 'IN_PROGRESS'];
 
+function getLoginCodeDeliveryMode() {
+  const mode = String(process.env.AUTH_LOGIN_CODE_DELIVERY ?? 'email')
+    .trim()
+    .toLowerCase();
+  if (mode !== 'email' && mode !== 'static') {
+    throw new Error('AUTH_LOGIN_CODE_DELIVERY must be either "email" or "static".');
+  }
+  return mode;
+}
+
 function toFloat(value) {
   return value == null ? null : Number(value);
 }
@@ -320,20 +330,6 @@ function invitationToken() {
   return crypto.randomBytes(24).toString('hex');
 }
 
-function buildDefaultFullName(email) {
-  const localPart = email.split('@')[0]?.trim();
-  if (!localPart) {
-    return 'Новый пользователь';
-  }
-
-  return localPart
-    .replace(/[._-]+/g, ' ')
-    .split(' ')
-    .filter(Boolean)
-    .map((part) => part.charAt(0).toUpperCase() + part.slice(1))
-    .join(' ');
-}
-
 function normalizeText(value) {
   return String(value ?? '').trim();
 }
@@ -1435,19 +1431,24 @@ export const resolvers = {
           },
         },
       });
+      if (!user) {
+        throw new Error('User is not invited to the cabinet.');
+      }
 
       const challenge = createLoginChallenge({
-        userId: user?.id ?? null,
+        userId: user.id,
         channel: input.channel,
         destination,
       });
 
       const code = getStaticAuthCode();
-      await sendLoginCodeEmail({
-        to: destination,
-        code,
-        expiresAt: challenge.expiresAt,
-      });
+      if (getLoginCodeDeliveryMode() === 'email') {
+        await sendLoginCodeEmail({
+          to: destination,
+          code,
+          expiresAt: challenge.expiresAt,
+        });
+      }
 
       return {
         challengeToken: challenge.challengeToken,
@@ -1463,24 +1464,9 @@ export const resolvers = {
         code: input.code,
       });
 
-      let user = challenge.userId
-        ? await context.prisma.user.findUnique({
-            where: { id: challenge.userId },
-          })
-        : null;
-
-      if (!user && challenge.channel === 'EMAIL') {
-        const email = String(challenge.destination).trim().toLowerCase();
-        user = await context.prisma.user.upsert({
-          where: { email },
-          update: {},
-          create: {
-            email,
-            fullName: buildDefaultFullName(email),
-            role: 'CLIENT',
-          },
-        });
-      }
+      const user = await context.prisma.user.findUnique({
+        where: { id: challenge.userId },
+      });
 
       if (!user) {
         throw new Error('User is not available for this login challenge.');