diff --git a/app/controllers/webhooks_controller.rb b/app/controllers/webhooks_controller.rb
index 7e588a2f4..fef02abb2 100644
--- a/app/controllers/webhooks_controller.rb
+++ b/app/controllers/webhooks_controller.rb
@@ -8,7 +8,7 @@ class WebhooksController < ApplicationController
   def receive
     case params[:source]
     when "stripe"
-      UserUpgrade.receive_webhook(request)
+      PaymentTransaction::Stripe.receive_webhook(request)
       head 200
     when "discord"
       json = DiscordSlashCommand.receive_webhook(request)
diff --git a/app/logical/payment_transaction.rb b/app/logical/payment_transaction.rb
new file mode 100644
index 000000000..3d0839f7a
--- /dev/null
+++ b/app/logical/payment_transaction.rb
@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+# A PaymentTransaction represents a payment in some payment processor's backend API.
+#
+# @see app/logical/payment_transaction/stripe.rb
+class PaymentTransaction
+  attr_reader :user_upgrade
+  delegate :recipient, :purchaser, :upgrade_type, :pending?, :stripe_id, to: :user_upgrade
+
+  def initialize(user_upgrade)
+    @user_upgrade = user_upgrade
+  end
+
+  # Initiate a new payment. Normally this sets up a checkout page with the payment processor, which
+  # we redirect the user to. When the payment succeeds, the user is redirected to a success page and
+  # the processor sends us a webhook, which we catch to finalize the upgrade. If the payment fails,
+  # the user is redirected to an error page and the upgrade doesn't go through.
+  #
+  # Normally this returns a processor-specific transaction object containing an ID or URL, which is
+  # used to redirect to the checkout page.
+  def create!(country: "US", allow_promotion_codes: false)
+    raise NotImplementedError
+  end
+
+  # Refund a completed payment to the purchaser.
+  def refund!
+    raise NotImplementedError
+  end
+
+  # Handle a webhook from the payment processor. Normally the payment processor sends us a webhook
+  # to notify us of successful payments, which we listen for to complete the upgrade.
+  def receive_webhook!(request)
+    raise NotImplementedError
+  end
+
+  # A public link to the payment processor's receipt for the transaction.
+  def receipt_url
+    nil
+  end
+
+  # A private link to the transaction in the payment processor's admin area.
+  def payment_url
+    nil
+  end
+
+  # The amount of money paid in the transaction.
+  def amount
+    nil
+  end
+
+  # The currency used in the transaction.
+  def currency
+    nil
+  end
+end
diff --git a/app/logical/payment_transaction/stripe.rb b/app/logical/payment_transaction/stripe.rb
new file mode 100644
index 000000000..7f6c1d4f5
--- /dev/null
+++ b/app/logical/payment_transaction/stripe.rb
@@ -0,0 +1,190 @@
+# frozen_string_literal: true
+
+class PaymentTransaction::Stripe < PaymentTransaction
+  delegate :stripe_id, to: :user_upgrade
+
+  def self.enabled?
+    Danbooru.config.stripe_secret_key.present? && Danbooru.config.stripe_publishable_key.present? && Danbooru.config.stripe_webhook_secret.present?
+  end
+
+  def create!(country: "US", allow_promotion_codes: false)
+    checkout_session = ::Stripe::Checkout::Session.create(
+      mode: "payment",
+      success_url: Routes.user_upgrade_url(user_upgrade),
+      cancel_url: Routes.new_user_upgrade_url(user_id: recipient.id),
+      client_reference_id: "user_upgrade_#{user_upgrade.id}",
+      customer_email: purchaser.email_address&.address,
+      payment_method_types: payment_method_types(country),
+      allow_promotion_codes: allow_promotion_codes.presence,
+      line_items: [{
+        price: upgrade_price_id(country),
+        quantity: 1,
+      }],
+      discounts: [{
+        coupon: promotion_discount_id,
+      }],
+      metadata: {
+        user_upgrade_id: user_upgrade.id,
+        purchaser_id: purchaser.id,
+        recipient_id: recipient.id,
+        purchaser_name: purchaser.name,
+        recipient_name: recipient.name,
+        upgrade_type: upgrade_type,
+        country: country,
+        is_gift: user_upgrade.is_gift?,
+        level: user_upgrade.level,
+      }
+    )
+
+    user_upgrade.update!(stripe_id: checkout_session.id)
+    checkout_session
+  end
+
+  def refund!(reason = nil)
+    ::Stripe::Refund.create(payment_intent: payment_intent.id, reason: reason)
+  end
+
+  concerning :WebhookMethods do
+    class_methods do
+      def receive_webhook(request)
+        event = build_event(request)
+
+        case event.type
+        when "checkout.session.completed"
+          checkout_session_completed(event.data.object)
+        when "charge.dispute.created"
+          charge_dispute_created(event.data.object)
+        when "radar.early_fraud_warning.created"
+          radar_early_fraud_warning_created(event.data.object)
+        end
+      end
+
+      private def build_event(request)
+        payload = request.body.read
+        signature = request.headers["Stripe-Signature"]
+        ::Stripe::Webhook.construct_event(payload, signature, Danbooru.config.stripe_webhook_secret)
+      end
+
+      private def checkout_session_completed(checkout)
+        user_upgrade = UserUpgrade.find(checkout.metadata.user_upgrade_id)
+        user_upgrade.process_upgrade!(checkout.payment_status)
+      end
+
+      private def charge_dispute_created(dispute)
+        Dmail.create_automated(to: User.owner, title: "Stripe Dispute", body: <<~EOS)
+          Dispute: https://stripe.com/payments/#{dispute.charge}
+        EOS
+      end
+
+      private def radar_early_fraud_warning_created(fraud_warning)
+        Dmail.create_automated(to: User.owner, title: "Stripe Early Fraud Warning", body: <<~EOS)
+          Charge: https://stripe.com/payments/#{fraud_warning.charge}
+        EOS
+      end
+
+      private def register_webhook
+        webhook = ::Stripe::WebhookEndpoint.create({
+          url: Routes.webhook_user_upgrade_url(source: "stripe"),
+          enabled_events: [
+            "checkout.session.completed",
+            "checkout.session.async_payment_failed",
+            "checkout.session.async_payment_succeeded",
+            "charge.dispute.created",
+            "radar.early_fraud_warning.created",
+          ],
+        })
+
+        webhook.secret
+      end
+    end
+  end
+
+  def receipt_url
+    return nil if pending? || stripe_id.nil?
+    charge.receipt_url
+  end
+
+  def payment_url
+    return nil if pending? || stripe_id.nil?
+    "https://dashboard.stripe.com/payments/#{payment_intent.id}"
+  end
+
+  def amount
+    payment_intent.amount
+  end
+
+  def currency
+    payment_intent.currency
+  end
+
+  private def checkout_session
+    return nil if stripe_id.nil?
+    @checkout_session ||= ::Stripe::Checkout::Session.retrieve(stripe_id)
+  end
+
+  private def payment_intent
+    return nil if checkout_session.nil?
+    @payment_intent ||= ::Stripe::PaymentIntent.retrieve(checkout_session.payment_intent)
+  end
+
+  private def charge
+    payment_intent.charges.data.first
+  end
+
+  private def payment_method_types(country)
+    case country.to_s.upcase
+    # Austria, https://stripe.com/docs/payments/bancontact
+    when "AT"
+      ["card", "eps"]
+    # Belgium, https://stripe.com/docs/payments/eps
+    when "BE"
+      ["card", "bancontact"]
+    # Germany, https://stripe.com/docs/payments/giropay
+    when "DE"
+      ["card", "giropay"]
+    # Netherlands, https://stripe.com/docs/payments/ideal
+    when "NL"
+      ["card", "ideal"]
+    # Poland, https://stripe.com/docs/payments/p24
+    when "PL"
+      ["card", "p24"]
+    else
+      ["card"]
+    end
+  end
+
+  private def preferred_currency(country)
+    case country.to_s.upcase
+    # Austria, Belgium, Germany, Netherlands, Poland
+    when "AT", "BE", "DE", "NL", "PL"
+      "eur"
+    else
+      "usd"
+    end
+  end
+
+  private def upgrade_price_id(country)
+    case [upgrade_type, preferred_currency(country)]
+    when ["gold", "usd"]
+      Danbooru.config.stripe_gold_usd_price_id
+    when ["gold", "eur"]
+      Danbooru.config.stripe_gold_eur_price_id
+    when ["platinum", "usd"]
+      Danbooru.config.stripe_platinum_usd_price_id
+    when ["platinum", "eur"]
+      Danbooru.config.stripe_platinum_eur_price_id
+    when ["gold_to_platinum", "usd"]
+      Danbooru.config.stripe_gold_to_platinum_usd_price_id
+    when ["gold_to_platinum", "eur"]
+      Danbooru.config.stripe_gold_to_platinum_eur_price_id
+    else
+      raise NotImplementedError
+    end
+  end
+
+  private def promotion_discount_id
+    if Danbooru.config.is_promotion?
+      Danbooru.config.stripe_promotion_discount_id
+    end
+  end
+end
diff --git a/app/models/user_upgrade.rb b/app/models/user_upgrade.rb
index fc9721c81..03c2d0dfb 100644
--- a/app/models/user_upgrade.rb
+++ b/app/models/user_upgrade.rb
@@ -4,6 +4,8 @@ class UserUpgrade < ApplicationRecord
   belongs_to :recipient, class_name: "User"
   belongs_to :purchaser, class_name: "User"
 
+  delegate :payment_url, :receipt_url, to: :transaction
+
   enum upgrade_type: {
     gold: 0,
     platinum: 10,
@@ -21,19 +23,7 @@ class UserUpgrade < ApplicationRecord
   scope :self_upgrade, -> { where("recipient_id = purchaser_id") }
 
   def self.enabled?
-    stripe_secret_key.present? && stripe_publishable_key.present? && stripe_webhook_secret.present?
-  end
-
-  def self.stripe_secret_key
-    Danbooru.config.stripe_secret_key
-  end
-
-  def self.stripe_publishable_key
-    Danbooru.config.stripe_publishable_key
-  end
-
-  def self.stripe_webhook_secret
-    Danbooru.config.stripe_webhook_secret
+    Danbooru.config.user_upgrades_enabled?
   end
 
   def self.gold_price
@@ -147,74 +137,23 @@ class UserUpgrade < ApplicationRecord
     end
   end
 
-  concerning :StripeMethods do
+  concerning :TransactionMethods do
     def create_checkout!(country: "US", allow_promotion_codes: false)
-      methods = payment_method_types(country)
-      currency = preferred_currency(country)
-      price_id = upgrade_price_id(currency)
-
-      checkout = Stripe::Checkout::Session.create(
-        mode: "payment",
-        success_url: Routes.user_upgrade_url(self),
-        cancel_url: Routes.new_user_upgrade_url(user_id: recipient.id),
-        client_reference_id: "user_upgrade_#{id}",
-        customer_email: purchaser.email_address&.address,
-        payment_method_types: methods,
-        allow_promotion_codes: allow_promotion_codes.presence,
-        line_items: [{
-          price: price_id,
-          quantity: 1,
-        }],
-        discounts: [{
-          coupon: promotion_discount_id,
-        }],
-        metadata: {
-          user_upgrade_id: id,
-          purchaser_id: purchaser.id,
-          recipient_id: recipient.id,
-          purchaser_name: purchaser.name,
-          recipient_name: recipient.name,
-          upgrade_type: upgrade_type,
-          country: country,
-          is_gift: is_gift?,
-          level: level,
-        }
-      )
-
-      update!(stripe_id: checkout.id)
-      checkout
+      transaction.create!(country: country, allow_promotion_codes: allow_promotion_codes)
     end
 
     def refund!(reason: nil)
       with_lock do
         return if refunded?
 
-        Stripe::Refund.create(payment_intent: payment_intent.id, reason: reason)
+        transaction.refund!(reason)
         recipient.update!(level: previous_level)
         update!(status: "refunded")
       end
     end
 
-    def receipt_url
-      return nil if pending? || stripe_id.nil?
-      charge.receipt_url
-    end
-
-    def payment_url
-      return nil if pending? || stripe_id.nil?
-      "https://dashboard.stripe.com/payments/#{payment_intent.id}"
-    end
-
-    def checkout_session
-      @checkout_session ||= Stripe::Checkout::Session.retrieve(stripe_id)
-    end
-
-    def payment_intent
-      @payment_intent ||= Stripe::PaymentIntent.retrieve(checkout_session.payment_intent)
-    end
-
-    def charge
-      payment_intent.charges.data.first
+    def transaction
+      PaymentTransaction::Stripe.new(self)
     end
 
     def has_receipt?
@@ -224,115 +163,5 @@ class UserUpgrade < ApplicationRecord
     def has_payment?
       !pending?
     end
-
-    def promotion_discount_id
-      if Danbooru.config.is_promotion?
-        Danbooru.config.stripe_promotion_discount_id
-      end
-    end
-
-    def upgrade_price_id(currency)
-      case [upgrade_type, currency]
-      when ["gold", "usd"]
-        Danbooru.config.stripe_gold_usd_price_id
-      when ["gold", "eur"]
-        Danbooru.config.stripe_gold_eur_price_id
-      when ["platinum", "usd"]
-        Danbooru.config.stripe_platinum_usd_price_id
-      when ["platinum", "eur"]
-        Danbooru.config.stripe_platinum_eur_price_id
-      when ["gold_to_platinum", "usd"]
-        Danbooru.config.stripe_gold_to_platinum_usd_price_id
-      when ["gold_to_platinum", "eur"]
-        Danbooru.config.stripe_gold_to_platinum_eur_price_id
-      else
-        raise NotImplementedError
-      end
-    end
-
-    def payment_method_types(country)
-      case country.to_s.upcase
-      # Austria, https://stripe.com/docs/payments/bancontact
-      when "AT"
-        ["card", "eps"]
-      # Belgium, https://stripe.com/docs/payments/eps
-      when "BE"
-        ["card", "bancontact"]
-      # Germany, https://stripe.com/docs/payments/giropay
-      when "DE"
-        ["card", "giropay"]
-      # Netherlands, https://stripe.com/docs/payments/ideal
-      when "NL"
-        ["card", "ideal"]
-      # Poland, https://stripe.com/docs/payments/p24
-      when "PL"
-        ["card", "p24"]
-      else
-        ["card"]
-      end
-    end
-
-    def preferred_currency(country)
-      case country.to_s.upcase
-      # Austria, Belgium, Germany, Netherlands, Poland
-      when "AT", "BE", "DE", "NL", "PL"
-        "eur"
-      else
-        "usd"
-      end
-    end
-
-    class_methods do
-      def register_webhook
-        webhook = Stripe::WebhookEndpoint.create({
-          url: Routes.webhook_user_upgrade_url(source: "stripe"),
-          enabled_events: [
-            "checkout.session.completed",
-            "checkout.session.async_payment_failed",
-            "checkout.session.async_payment_succeeded",
-            "charge.dispute.created",
-            "radar.early_fraud_warning.created",
-          ],
-        })
-
-        webhook.secret
-      end
-
-      def receive_webhook(request)
-        event = build_event(request)
-
-        case event.type
-        when "checkout.session.completed"
-          checkout_session_completed(event.data.object)
-        when "charge.dispute.created"
-          charge_dispute_created(event.data.object)
-        when "radar.early_fraud_warning.created"
-          radar_early_fraud_warning_created(event.data.object)
-        end
-      end
-
-      def build_event(request)
-        payload = request.body.read
-        signature = request.headers["Stripe-Signature"]
-        Stripe::Webhook.construct_event(payload, signature, stripe_webhook_secret)
-      end
-
-      def checkout_session_completed(checkout)
-        user_upgrade = UserUpgrade.find(checkout.metadata.user_upgrade_id)
-        user_upgrade.process_upgrade!(checkout.payment_status)
-      end
-
-      def charge_dispute_created(dispute)
-        Dmail.create_automated(to: User.owner, title: "Stripe Dispute", body: <<~EOS)
-          Dispute: https://stripe.com/payments/#{dispute.charge}
-        EOS
-      end
-
-      def radar_early_fraud_warning_created(fraud_warning)
-        Dmail.create_automated(to: User.owner, title: "Stripe Early Fraud Warning", body: <<~EOS)
-          Charge: https://stripe.com/payments/#{fraud_warning.charge}
-        EOS
-      end
-    end
   end
 end
diff --git a/app/views/user_upgrades/create.js.erb b/app/views/user_upgrades/create.js.erb
index e08bc3438..e57465e98 100644
--- a/app/views/user_upgrades/create.js.erb
+++ b/app/views/user_upgrades/create.js.erb
@@ -1,2 +1,2 @@
-var stripe = Stripe("<%= j UserUpgrade.stripe_publishable_key %>");
+var stripe = Stripe("<%= j Danbooru.config.stripe_publishable_key %>");
 stripe.redirectToCheckout({ sessionId: "<%= j @checkout.id %>" });
diff --git a/config/danbooru_default_config.rb b/config/danbooru_default_config.rb
index 50094e871..23dcce551 100644
--- a/config/danbooru_default_config.rb
+++ b/config/danbooru_default_config.rb
@@ -363,6 +363,11 @@ module Danbooru
       resolution_mismatch source_larger source_smaller]
     end
 
+    # Whether the Gold account upgrade page should be enabled.
+    def user_upgrades_enabled?
+      true
+    end
+
     def stripe_secret_key
     end
 
diff --git a/test/functional/webhooks_controller_test.rb b/test/functional/webhooks_controller_test.rb
index c39d08d0a..e6dd44ea4 100644
--- a/test/functional/webhooks_controller_test.rb
+++ b/test/functional/webhooks_controller_test.rb
@@ -9,8 +9,8 @@ class WebhooksControllerTest < ActionDispatch::IntegrationTest
     StripeMock.stop
   end
 
-  def post_webhook(*args, metadata: {}, payment_status: "paid")
-    skip unless UserUpgrade.enabled?
+  def post_stripe_webhook(*args, metadata: {}, payment_status: "paid")
+    skip unless PaymentTransaction::Stripe.enabled?
     event = StripeMock.mock_webhook_event(*args, payment_status: payment_status, metadata: metadata)
     signature = generate_stripe_signature(event)
     headers = { "Stripe-Signature": signature }
@@ -22,7 +22,7 @@ class WebhooksControllerTest < ActionDispatch::IntegrationTest
   # https://stripe.com/docs/webhooks/signatures
   def generate_stripe_signature(event)
     time = Time.now
-    secret = UserUpgrade.stripe_webhook_secret
+    secret = Danbooru.config.stripe_webhook_secret
     signature = Stripe::Webhook::Signature.compute_signature(time, event.to_json, secret)
     Stripe::Webhook::Signature.generate_header(time, signature, scheme: Stripe::Webhook::Signature::EXPECTED_SCHEME)
   end
@@ -58,7 +58,7 @@ class WebhooksControllerTest < ActionDispatch::IntegrationTest
 
         context "for a payment_intent.created event" do
           should "work" do
-            post_webhook("payment_intent.created")
+            post_stripe_webhook("payment_intent.created")
 
             assert_response 200
           end
@@ -68,7 +68,7 @@ class WebhooksControllerTest < ActionDispatch::IntegrationTest
           context "for completed event with an unpaid payment status" do
             should "not upgrade the user" do
               @user_upgrade = create(:self_gold_upgrade)
-              post_webhook("checkout.session.completed", metadata: { user_upgrade_id: @user_upgrade.id }, payment_status: "unpaid")
+              post_stripe_webhook("checkout.session.completed", metadata: { user_upgrade_id: @user_upgrade.id }, payment_status: "unpaid")
 
               assert_response 200
               assert_equal("processing", @user_upgrade.reload.status)
@@ -80,7 +80,7 @@ class WebhooksControllerTest < ActionDispatch::IntegrationTest
             context "to Gold" do
               should "upgrade the user" do
                 @user_upgrade = create(:self_gold_upgrade)
-                post_webhook("checkout.session.completed", metadata: { user_upgrade_id: @user_upgrade.id })
+                post_stripe_webhook("checkout.session.completed", metadata: { user_upgrade_id: @user_upgrade.id })
 
                 assert_response 200
                 assert_equal("complete", @user_upgrade.reload.status)
@@ -91,7 +91,7 @@ class WebhooksControllerTest < ActionDispatch::IntegrationTest
             context "to Platinum" do
               should "upgrade the user" do
                 @user_upgrade = create(:self_platinum_upgrade)
-                post_webhook("checkout.session.completed", metadata: { user_upgrade_id: @user_upgrade.id })
+                post_stripe_webhook("checkout.session.completed", metadata: { user_upgrade_id: @user_upgrade.id })
 
                 assert_response 200
                 assert_equal("complete", @user_upgrade.reload.status)
@@ -102,7 +102,7 @@ class WebhooksControllerTest < ActionDispatch::IntegrationTest
             context "from Gold to Platinum" do
               should "upgrade the user" do
                 @user_upgrade = create(:self_gold_to_platinum_upgrade)
-                post_webhook("checkout.session.completed", metadata: { user_upgrade_id: @user_upgrade.id })
+                post_stripe_webhook("checkout.session.completed", metadata: { user_upgrade_id: @user_upgrade.id })
 
                 assert_response 200
                 assert_equal("complete", @user_upgrade.reload.status)
@@ -115,7 +115,7 @@ class WebhooksControllerTest < ActionDispatch::IntegrationTest
             context "to Gold" do
               should "upgrade the user" do
                 @user_upgrade = create(:gift_gold_upgrade)
-                post_webhook("checkout.session.completed", metadata: { user_upgrade_id: @user_upgrade.id })
+                post_stripe_webhook("checkout.session.completed", metadata: { user_upgrade_id: @user_upgrade.id })
 
                 assert_response 200
                 assert_equal("complete", @user_upgrade.reload.status)
@@ -126,7 +126,7 @@ class WebhooksControllerTest < ActionDispatch::IntegrationTest
             context "to Platinum" do
               should "upgrade the user" do
                 @user_upgrade = create(:gift_platinum_upgrade)
-                post_webhook("checkout.session.completed", metadata: { user_upgrade_id: @user_upgrade.id })
+                post_stripe_webhook("checkout.session.completed", metadata: { user_upgrade_id: @user_upgrade.id })
 
                 assert_response 200
                 assert_equal("complete", @user_upgrade.reload.status)
@@ -137,7 +137,7 @@ class WebhooksControllerTest < ActionDispatch::IntegrationTest
             context "from Gold to Platinum" do
               should "upgrade the user" do
                 @user_upgrade = create(:gift_gold_to_platinum_upgrade)
-                post_webhook("checkout.session.completed", metadata: { user_upgrade_id: @user_upgrade.id })
+                post_stripe_webhook("checkout.session.completed", metadata: { user_upgrade_id: @user_upgrade.id })
 
                 assert_response 200
                 assert_equal("complete", @user_upgrade.reload.status)
diff --git a/test/test_helpers/stripe_test_helper.rb b/test/test_helpers/stripe_test_helper.rb
index 9bfc845f9..8d1d7589c 100644
--- a/test/test_helpers/stripe_test_helper.rb
+++ b/test/test_helpers/stripe_test_helper.rb
@@ -3,11 +3,11 @@ StripeMock.webhook_fixture_path = "test/fixtures/stripe-webhooks"
 module StripeTestHelper
   def mock_stripe!
     setup do
-      StripeMock.start unless UserUpgrade.enabled?
+      StripeMock.start unless PaymentTransaction::Stripe.enabled?
     end
 
     teardown do
-      StripeMock.stop unless UserUpgrade.enabled?
+      StripeMock.stop unless PaymentTransaction::Stripe.enabled?
     end
   end
 end
diff --git a/test/unit/user_upgrade_test.rb b/test/unit/user_upgrade_test.rb
index 84b1f7961..a233dceb7 100644
--- a/test/unit/user_upgrade_test.rb
+++ b/test/unit/user_upgrade_test.rb
@@ -44,7 +44,7 @@ class UserUpgradeTest < ActiveSupport::TestCase
       context "for a gifted upgrade" do
         context "to Gold" do
           should "prefill the Stripe checkout page with the purchaser's email address" do
-            skip "Stripe API keys not configured" unless UserUpgrade.enabled?
+            skip "Stripe API keys not configured" unless PaymentTransaction::Stripe.enabled?
 
             @user = create(:user, email_address: build(:email_address))
             @user_upgrade = create(:gift_gold_upgrade, purchaser: @user)
@@ -64,48 +64,48 @@ class UserUpgradeTest < ActiveSupport::TestCase
           @user_upgrade = create(:self_gold_upgrade)
           @checkout = @user_upgrade.create_checkout!(country: "US")
 
-          assert_equal(UserUpgrade.gold_price, @user_upgrade.payment_intent.amount)
-          assert_equal("usd", @user_upgrade.payment_intent.currency)
+          assert_equal(UserUpgrade.gold_price, @user_upgrade.transaction.amount)
+          assert_equal("usd", @user_upgrade.transaction.currency)
         end
 
         should "choose the right price in USD for a platinum upgrade" do
           @user_upgrade = create(:self_platinum_upgrade)
           @checkout = @user_upgrade.create_checkout!(country: "US")
 
-          assert_equal(UserUpgrade.platinum_price, @user_upgrade.payment_intent.amount)
-          assert_equal("usd", @user_upgrade.payment_intent.currency)
+          assert_equal(UserUpgrade.platinum_price, @user_upgrade.transaction.amount)
+          assert_equal("usd", @user_upgrade.transaction.currency)
         end
 
         should "choose the right price in USD for a gold to platinum upgrade" do
           @user_upgrade = create(:self_gold_to_platinum_upgrade)
           @checkout = @user_upgrade.create_checkout!(country: "US")
 
-          assert_equal(UserUpgrade.gold_to_platinum_price, @user_upgrade.payment_intent.amount)
-          assert_equal("usd", @user_upgrade.payment_intent.currency)
+          assert_equal(UserUpgrade.gold_to_platinum_price, @user_upgrade.transaction.amount)
+          assert_equal("usd", @user_upgrade.transaction.currency)
         end
 
         should "choose the right price in EUR for a gold upgrade" do
           @user_upgrade = create(:self_gold_upgrade)
           @checkout = @user_upgrade.create_checkout!(country: "DE")
 
-          assert_equal(0.8 * UserUpgrade.gold_price, @user_upgrade.payment_intent.amount)
-          assert_equal("eur", @user_upgrade.payment_intent.currency)
+          assert_equal(0.8 * UserUpgrade.gold_price, @user_upgrade.transaction.amount)
+          assert_equal("eur", @user_upgrade.transaction.currency)
         end
 
         should "choose the right price in EUR for a platinum upgrade" do
           @user_upgrade = create(:self_platinum_upgrade)
           @checkout = @user_upgrade.create_checkout!(country: "DE")
 
-          assert_equal(0.8 * UserUpgrade.platinum_price, @user_upgrade.payment_intent.amount)
-          assert_equal("eur", @user_upgrade.payment_intent.currency)
+          assert_equal(0.8 * UserUpgrade.platinum_price, @user_upgrade.transaction.amount)
+          assert_equal("eur", @user_upgrade.transaction.currency)
         end
 
         should "choose the right price in EUR for a gold to platinum upgrade" do
           @user_upgrade = create(:self_gold_to_platinum_upgrade)
           @checkout = @user_upgrade.create_checkout!(country: "DE")
 
-          assert_equal(0.8 * UserUpgrade.gold_to_platinum_price, @user_upgrade.payment_intent.amount)
-          assert_equal("eur", @user_upgrade.payment_intent.currency)
+          assert_equal(0.8 * UserUpgrade.gold_to_platinum_price, @user_upgrade.transaction.amount)
+          assert_equal("eur", @user_upgrade.transaction.currency)
         end
       end
 
@@ -119,49 +119,49 @@ class UserUpgradeTest < ActiveSupport::TestCase
           @checkout = @user_upgrade.create_checkout!(country: "US")
 
           assert_equal(["card"], @checkout.payment_method_types)
-          assert_equal("usd", @user_upgrade.payment_intent.currency)
+          assert_equal("usd", @user_upgrade.transaction.currency)
         end
 
         should "choose the right payment methods for AT" do
           @checkout = @user_upgrade.create_checkout!(country: "AT")
 
           assert_equal(["card", "eps"], @checkout.payment_method_types)
-          assert_equal("eur", @user_upgrade.payment_intent.currency)
+          assert_equal("eur", @user_upgrade.transaction.currency)
         end
 
         should "choose the right payment methods for BE" do
           @checkout = @user_upgrade.create_checkout!(country: "BE")
 
           assert_equal(["card", "bancontact"], @checkout.payment_method_types)
-          assert_equal("eur", @user_upgrade.payment_intent.currency)
+          assert_equal("eur", @user_upgrade.transaction.currency)
         end
 
         should "choose the right payment methods for DE" do
           @checkout = @user_upgrade.create_checkout!(country: "DE")
 
           assert_equal(["card", "giropay"], @checkout.payment_method_types)
-          assert_equal("eur", @user_upgrade.payment_intent.currency)
+          assert_equal("eur", @user_upgrade.transaction.currency)
         end
 
         should "choose the right payment methods for NL" do
           @checkout = @user_upgrade.create_checkout!(country: "NL")
 
           assert_equal(["card", "ideal"], @checkout.payment_method_types)
-          assert_equal("eur", @user_upgrade.payment_intent.currency)
+          assert_equal("eur", @user_upgrade.transaction.currency)
         end
 
         should "choose the right payment methods for PL" do
           @checkout = @user_upgrade.create_checkout!(country: "PL")
 
           assert_equal(["card", "p24"], @checkout.payment_method_types)
-          assert_equal("eur", @user_upgrade.payment_intent.currency)
+          assert_equal("eur", @user_upgrade.transaction.currency)
         end
 
         should "choose the right payment methods for an unsupported country" do
           @checkout = @user_upgrade.create_checkout!(country: "MX")
 
           assert_equal(["card"], @checkout.payment_method_types)
-          assert_equal("usd", @user_upgrade.payment_intent.currency)
+          assert_equal("usd", @user_upgrade.transaction.currency)
         end
       end
     end