diff --git a/enterprise/app/controllers/enterprise/api/v1/accounts/concerns/billing_v2.rb b/enterprise/app/controllers/enterprise/api/v1/accounts/concerns/billing_v2.rb
index 1d38466d2..01d899279 100644
--- a/enterprise/app/controllers/enterprise/api/v1/accounts/concerns/billing_v2.rb
+++ b/enterprise/app/controllers/enterprise/api/v1/accounts/concerns/billing_v2.rb
@@ -53,7 +53,7 @@ module Enterprise::Api::V1::Accounts::Concerns::BillingV2
     )
 
     if result[:success]
-      render json: { success: true, redirect_url: result[:redirect_url], checkout_session_id: result[:checkout_session_id] }
+      render json: { success: true, redirect_url: result[:redirect_url], session_id: result[:session_id] }
     else
       render json: { error: result[:message] }, status: :unprocessable_entity
     end
diff --git a/enterprise/app/services/enterprise/billing/v2/base_service.rb b/enterprise/app/services/enterprise/billing/v2/base_service.rb
index 92da4f306..507ffd6bd 100644
--- a/enterprise/app/services/enterprise/billing/v2/base_service.rb
+++ b/enterprise/app/services/enterprise/billing/v2/base_service.rb
@@ -50,10 +50,4 @@ class Enterprise::Billing::V2::BaseService
   def with_locked_account(&)
     account.with_lock(&)
   end
-
-  def with_stripe_error_handling
-    yield
-  rescue Stripe::StripeError => e
-    { success: false, message: e.message }
-  end
 end
diff --git a/enterprise/app/services/enterprise/billing/v2/credit_management_service.rb b/enterprise/app/services/enterprise/billing/v2/credit_management_service.rb
index 77f7a93cf..e21c0ce66 100644
--- a/enterprise/app/services/enterprise/billing/v2/credit_management_service.rb
+++ b/enterprise/app/services/enterprise/billing/v2/credit_management_service.rb
@@ -32,8 +32,7 @@ class Enterprise::Billing::V2::CreditManagementService < Enterprise::Billing::V2
     return [] if customer_id.blank?
 
     response = Stripe::Billing::CreditGrant.list(
-      { customer: customer_id, limit: 100 },
-      stripe_api_options
+      { customer: customer_id, limit: 100 }
     )
 
     grants = response.data.map do |grant|
@@ -87,8 +86,4 @@ class Enterprise::Billing::V2::CreditManagementService < Enterprise::Billing::V2
   def stripe_customer_id
     custom_attribute('stripe_customer_id')
   end
-
-  def stripe_api_options
-    { api_key: ENV.fetch('STRIPE_SECRET_KEY', nil), stripe_version: '2025-08-27.preview' }
-  end
 end
diff --git a/enterprise/app/services/enterprise/billing/v2/plan_catalog.rb b/enterprise/app/services/enterprise/billing/v2/plan_catalog.rb
index 390049eba..50f38d4a0 100644
--- a/enterprise/app/services/enterprise/billing/v2/plan_catalog.rb
+++ b/enterprise/app/services/enterprise/billing/v2/plan_catalog.rb
@@ -93,11 +93,10 @@ module Enterprise::Billing::V2::PlanCatalog
     }
   end
 
-  def rate_card_component(definition)
+  def rate_card_component(_definition)
     {
       type: 'rate_card',
       name: 'Overage Rate',
-      overage_rate: definition[:overage_rate],
       rate_unit: CREDIT_UNIT,
       meter_id: nil
     }
diff --git a/enterprise/app/services/enterprise/billing/v2/topup_service.rb b/enterprise/app/services/enterprise/billing/v2/topup_service.rb
index 018b204b9..e0bdcf6f0 100644
--- a/enterprise/app/services/enterprise/billing/v2/topup_service.rb
+++ b/enterprise/app/services/enterprise/billing/v2/topup_service.rb
@@ -102,8 +102,7 @@ class Enterprise::Billing::V2::TopupService < Enterprise::Billing::V2::BaseServi
   # Following Stripe UBB Integration Guide section 8
   def create_stripe_credit_grant(amount_cents, currency, credits)
     Stripe::Billing::CreditGrant.create(
-      credit_grant_params(amount_cents, currency, credits),
-      stripe_api_options
+      credit_grant_params(amount_cents, currency, credits)
     )
   end
 
@@ -149,8 +148,4 @@ class Enterprise::Billing::V2::TopupService < Enterprise::Billing::V2::BaseServi
   def stripe_customer_id
     custom_attribute('stripe_customer_id')
   end
-
-  def stripe_api_options
-    { api_key: ENV.fetch('STRIPE_SECRET_KEY', nil), stripe_version: '2025-08-27.preview' }
-  end
 end