diff --git a/apps/users/migrations/0007_alter_user_otp.py b/apps/users/migrations/0007_alter_user_otp.py
new file mode 100644
index 0000000..1d5a7b9
--- /dev/null
+++ b/apps/users/migrations/0007_alter_user_otp.py
@@ -0,0 +1,18 @@
+# Generated by Django 5.1.4 on 2025-11-18 11:40
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('users', '0006_alter_user_avatar'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='user',
+            name='otp',
+            field=models.CharField(blank=True, max_length=128, null=True, verbose_name='otp'),
+        ),
+    ]
diff --git a/apps/users/models.py b/apps/users/models.py
index e4b4e46..00fa21e 100644
--- a/apps/users/models.py
+++ b/apps/users/models.py
@@ -5,6 +5,7 @@ from datetime import timedelta
 # import service_clients
 from django.conf import settings
 from django.contrib.auth.base_user import BaseUserManager
+from django.contrib.auth.hashers import make_password
 from django.contrib.auth.models import AbstractUser
 from django.contrib.auth.validators import UnicodeUsernameValidator
 from django.db import models
@@ -34,7 +35,7 @@ class UserManager(BaseUserManager):
         # TODO: validate phone number
         user = self.model(phone_number=phone_number, username=username, email=email, **extra_fields)
         user.set_password(password)
-        user.set_otp()
+        # user.set_otp()
         user.date_joined = timezone.now()
         user.save(using=self._db)
 
@@ -113,7 +114,7 @@ class User(AbstractUser):
         null=True
     )
     phone_number = models.CharField(_('phone number'), max_length=30, blank=True, null=True, unique=True)
-    otp = models.CharField(_('otp'), max_length=6, blank=True, null=True)
+    otp = models.CharField(_('otp'), max_length=128, blank=True, null=True)
     otp_expire = models.DateTimeField(_('otp expire'), blank=True, null=True)
     otp_try = models.IntegerField(_('otp try'), blank=True, null=True, default=0)
 
@@ -151,7 +152,11 @@ class User(AbstractUser):
         return state.get_province_by_id(self.province)
 
     def set_otp(self):
-        self.otp = '77501'
+        if self.otp_expire and (self.otp_expire + timedelta(seconds=MAX_OTP_VALID_DURATION)) > timezone.now():
+            raise Exception('otp expire time not reached.')
+
+        self._otp = '77501'
+        self.otp = make_password(self._otp)
         # if settings.DEBUG or self.phone_number in DEVELOPMENT_PHONE_NUMBERS:
         #     self.otp = '77501'
         #
@@ -168,10 +173,10 @@ class User(AbstractUser):
         self.ott_expire = timezone.now() + timedelta(seconds=MAX_OTP_VALID_DURATION)
 
     def otp_is_valid(self):
-        return bool(self.otp and timezone.now() <= self.otp_expire)
+        return bool(self.otp and self.otp_expire and timezone.now() <= self.otp_expire)
 
     def ott_is_valid(self):
-        return bool(self.ott and timezone.now() <= self.ott_expire)
+        return bool(self.ott and self.ott_expire and timezone.now() <= self.ott_expire)
 
     def check_otp(self, otp):
         if self.otp_try <= MAX_OTP_TRY:
@@ -221,8 +226,8 @@ class User(AbstractUser):
         return result
 
     def send_otp(self):
-        print(self.otp)
-        self.notify(body=str(self.otp), title='OTP')
+        print(self._otp)
+        self.notify(body=str(self._otp), title='OTP')
 
     def notify(self, body, title=None, notification_type='sms'):
         message = ("وینسو"
diff --git a/apps/users/serializers.py b/apps/users/serializers.py
index 4e07bb7..a0ec8b9 100644
--- a/apps/users/serializers.py
+++ b/apps/users/serializers.py
@@ -5,6 +5,8 @@ from apps.users.models import User
 from django.utils import timezone
 from django.utils.translation import gettext_lazy as _
 
+from utils.exceptions import UnprocessableEntity
+
 phone_number_validator = RegexValidator(regex=r'^\+98[1-9]\d{9}$', message=_(
         "Phone number must be entered in the format: '+989999999999'."
     ),)
@@ -70,8 +72,10 @@ class RequestOTPSerializer(serializers.ModelSerializer):
         if not user.otp_is_valid():
             user.set_otp()
             user.save()
+            user.send_otp()
 
-        user.send_otp()
+        else:
+            raise UnprocessableEntity()
 
         self.instance = user
         return user
diff --git a/utils/exceptions.py b/utils/exceptions.py
index 28a4f95..756d9a4 100644
--- a/utils/exceptions.py
+++ b/utils/exceptions.py
@@ -47,4 +47,10 @@ class ErrorMiddleware:
                 "details": str(exception)  # فقط در حالت توسعه! در تولید بهتر است لاگ شود.
             },
             status=500
-        )
\ No newline at end of file
+        )
+
+
+class UnprocessableEntity(APIException):
+    status_code = 422
+    default_detail = 'The request was well-formed but cannot be processed due to semantic errors.'
+    default_code = 'unprocessable_entity'
\ No newline at end of file