diff --git a/decidim-budgets/app/commands/decidim/budgets/add_line_item.rb b/decidim-budgets/app/commands/decidim/budgets/add_line_item.rb
index ab2f512ceb520..551734bf102f2 100644
--- a/decidim-budgets/app/commands/decidim/budgets/add_line_item.rb
+++ b/decidim-budgets/app/commands/decidim/budgets/add_line_item.rb
@@ -23,7 +23,7 @@ def initialize(current_order, project, current_user)
       # Returns nothing.
       def call
         transaction do
-          return broadcast(:invalid) if voting_not_enabled? || order.checked_out?
+          return broadcast(:invalid) if voting_not_enabled? || order.checked_out? || exceeds_budget?
 
           add_line_item
           broadcast(:ok, order)
@@ -44,6 +44,10 @@ def add_line_item
         end
       end
 
+      def exceeds_budget?
+        order.allocation_for(project) + order.total > project.budget.total_budget
+      end
+
       def voting_not_enabled?
         project.component.current_settings.votes != "enabled"
       end
diff --git a/decidim-budgets/app/controllers/decidim/budgets/line_items_controller.rb b/decidim-budgets/app/controllers/decidim/budgets/line_items_controller.rb
index 227612c0b8a4b..f81b01e2f3ed9 100644
--- a/decidim-budgets/app/controllers/decidim/budgets/line_items_controller.rb
+++ b/decidim-budgets/app/controllers/decidim/budgets/line_items_controller.rb
@@ -20,7 +20,7 @@ def create
             end
 
             on(:invalid) do
-              render nothing: true, status: :unprocessable_entity
+              format.js { render "update_budget", status: :unprocessable_entity }
             end
           end
         end
@@ -35,7 +35,7 @@ def destroy
             end
 
             on(:invalid) do
-              render nothing: true, status: :unprocessable_entity
+              format.js { render "update_budget", status: :unprocessable_entity }
             end
           end
         end