diff --git a/billing/migrations/0008_alter_topup_options_topup_expired_topup_expires_at.py b/billing/migrations/0008_alter_topup_options_topup_expired_topup_expires_at.py
new file mode 100644
index 0000000..46cd966
--- /dev/null
+++ b/billing/migrations/0008_alter_topup_options_topup_expired_topup_expires_at.py
@@ -0,0 +1,26 @@
+# Generated by Django 5.2 on 2025-07-04 06:10
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("billing", "0007_topup_paid_at"),
+    ]
+
+    operations = [
+        migrations.AlterModelOptions(
+            name="topup",
+            options={"ordering": ["-created_at"]},
+        ),
+        migrations.AddField(
+            model_name="topup",
+            name="expired",
+            field=models.BooleanField(default=False),
+        ),
+        migrations.AddField(
+            model_name="topup",
+            name="expires_at",
+            field=models.DateTimeField(blank=True, null=True),
+        ),
+    ]
diff --git a/billing/migrations/0009_remove_topup_expired.py b/billing/migrations/0009_remove_topup_expired.py
new file mode 100644
index 0000000..71c5576
--- /dev/null
+++ b/billing/migrations/0009_remove_topup_expired.py
@@ -0,0 +1,16 @@
+# Generated by Django 5.2 on 2025-07-04 11:13
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("billing", "0008_alter_topup_options_topup_expired_topup_expires_at"),
+    ]
+
+    operations = [
+        migrations.RemoveField(
+            model_name="topup",
+            name="expired",
+        ),
+    ]
diff --git a/billing/models.py b/billing/models.py
index 8017793..8fee3d6 100644
--- a/billing/models.py
+++ b/billing/models.py
@@ -53,9 +53,16 @@ class Topup(models.Model):
     paid = models.BooleanField(default=False)
     paid_at = models.DateTimeField(null=True, blank=True)
     mib_reference = models.CharField(default="", null=True, blank=True)
+    expires_at = models.DateTimeField(null=True, blank=True)
     created_at = models.DateTimeField(default=timezone.now)
     updated_at = models.DateTimeField(auto_now=True)
 
+    @property
+    def is_expired(self):
+        if self.expires_at is None:
+            return False
+        return timezone.now() > self.expires_at
+
     def __str__(self):
         return f"Topup for {self.user}"