diff --git a/raystack/frontier/v1beta1/models.proto b/raystack/frontier/v1beta1/models.proto
index 21eddfb3..a2486ae9 100644
--- a/raystack/frontier/v1beta1/models.proto
+++ b/raystack/frontier/v1beta1/models.proto
@@ -860,6 +860,11 @@ message CheckoutSubscriptionBody {
   string plan = 1;
   bool skip_trial = 2;
   bool cancel_after_trial = 3;
+
+  // provider_coupon_id is the coupon code that will be applied to the subscription
+  // generated by the billing provider, this will be deprecated once coupons are
+  // managed by the platform
+  string provider_coupon_id = 4;
 }
 
 message CheckoutProductBody {