diff --git a/billing/migrations/0013_payment_expiry_notification_sent.py b/billing/migrations/0013_payment_expiry_notification_sent.py
new file mode 100644
index 0000000..0b5a10d
--- /dev/null
+++ b/billing/migrations/0013_payment_expiry_notification_sent.py
@@ -0,0 +1,17 @@
+# Generated by Django 5.2 on 2025-07-09 14:50
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("billing", "0012_payment_status"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="payment",
+            name="expiry_notification_sent",
+            field=models.BooleanField(default=False),
+        ),
+    ]
diff --git a/billing/models.py b/billing/models.py
index 8ddddbb..f8b6f8a 100644
--- a/billing/models.py
+++ b/billing/models.py
@@ -23,6 +23,7 @@ class Payment(models.Model):
     user = models.ForeignKey(User, on_delete=models.CASCADE, related_name="payments")
     paid_at = models.DateTimeField(null=True, blank=True)
     method = models.CharField(max_length=255, choices=PAYMENT_TYPES, default="TRANSFER")
+    expiry_notification_sent = models.BooleanField(default=False)
     expires_at = models.DateTimeField(null=True, blank=True)
     created_at = models.DateTimeField(default=timezone.now)
     updated_at = models.DateTimeField(auto_now=True)