diff --git a/app/controllers/api/products_controller.rb b/app/controllers/api/products_controller.rb
index 97f648fa3..a77d06e67 100644
--- a/app/controllers/api/products_controller.rb
+++ b/app/controllers/api/products_controller.rb
@@ -40,7 +40,7 @@ class API::ProductsController < API::ApiController
 
   def destroy
     authorize @product
-    @product.destroy
+    ProductService.destroy(@product)
     head :no_content
   end
 
diff --git a/app/exceptions/cannot_delete_product_error.rb b/app/exceptions/cannot_delete_product_error.rb
new file mode 100644
index 000000000..f4e2eec80
--- /dev/null
+++ b/app/exceptions/cannot_delete_product_error.rb
@@ -0,0 +1,3 @@
+# Raised when delete a product if this product has used in order
+class CannotDeleteProductError < StandardError
+end
diff --git a/app/exceptions/cart/item_amount_error.rb b/app/exceptions/cart/item_amount_error.rb
new file mode 100644
index 000000000..9085d68ce
--- /dev/null
+++ b/app/exceptions/cart/item_amount_error.rb
@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+# Raised when the item's amount != product's amount
+class Cart::ItemAmountError < StandardError
+end
diff --git a/app/exceptions/cart/quantity_min_error.rb b/app/exceptions/cart/quantity_min_error.rb
new file mode 100644
index 000000000..f34e4c1b2
--- /dev/null
+++ b/app/exceptions/cart/quantity_min_error.rb
@@ -0,0 +1,5 @@
+# frozen_string_literal: true
+
+# Raised when the item's quantity < product's quantity min
+class Cart::QuantityMinError < StandardError
+end
diff --git a/app/frontend/src/javascript/components/form/form-input.tsx b/app/frontend/src/javascript/components/form/form-input.tsx
index 31b04bec1..78f15d801 100644
--- a/app/frontend/src/javascript/components/form/form-input.tsx
+++ b/app/frontend/src/javascript/components/form/form-input.tsx
@@ -59,7 +59,7 @@ export const FormInput = <TFieldValues extends FieldValues, TInputType>({ id, re
           {...register(id as FieldPath<TFieldValues>, {
             ...rules,
             valueAsDate: type === 'date',
-            setValueAs: v => (v === null && nullable) ? null : (type === 'number' ? parseInt(v, 10) : v),
+            setValueAs: v => (v === null && nullable) ? null : (type === 'number' ? parseFloat(v) : v),
             value: defaultValue as FieldPathValue<TFieldValues, FieldPath<TFieldValues>>,
             onChange: (e) => { handleChange(e); }
           })}
diff --git a/app/frontend/src/javascript/components/store/product-form.tsx b/app/frontend/src/javascript/components/store/product-form.tsx
index 6bb1a36d6..07296e1be 100644
--- a/app/frontend/src/javascript/components/store/product-form.tsx
+++ b/app/frontend/src/javascript/components/store/product-form.tsx
@@ -280,7 +280,7 @@ export const ProductForm: React.FC<ProductFormProps> = ({ product, title, onSucc
                 <FormInput id="amount"
                             type="number"
                             register={register}
-                            rules={{ required: true, min: 0.01 }}
+                            rules={{ required: true, min: 0 }}
                             step={0.01}
                             formState={formState}
                             label={t('app.admin.store.product_form.price')} />
diff --git a/app/frontend/src/javascript/components/store/product-item.tsx b/app/frontend/src/javascript/components/store/product-item.tsx
index 177f460e7..c37f97dc1 100644
--- a/app/frontend/src/javascript/components/store/product-item.tsx
+++ b/app/frontend/src/javascript/components/store/product-item.tsx
@@ -79,12 +79,10 @@ export const ProductItem: React.FC<ProductItemProps> = ({ product, onEdit, onDel
           <span>{t('app.admin.store.product_item.stock.external')}</span>
           <p>{product.stock.external}</p>
         </div>
-        {product.amount &&
-          <div className='price'>
-            <p>{FormatLib.price(product.amount)}</p>
-            <span>/ {t('app.admin.store.product_item.unit')}</span>
-          </div>
-        }
+        <div className='price'>
+          <p>{FormatLib.price(product.amount || 0)}</p>
+          <span>/ {t('app.admin.store.product_item.unit')}</span>
+        </div>
       </div>
       <div className='actions'>
         <div className='manage'>
diff --git a/app/frontend/src/javascript/components/store/store-product-item.tsx b/app/frontend/src/javascript/components/store/store-product-item.tsx
index fef8d883a..321dc4b1e 100644
--- a/app/frontend/src/javascript/components/store/store-product-item.tsx
+++ b/app/frontend/src/javascript/components/store/store-product-item.tsx
@@ -81,12 +81,10 @@ export const StoreProductItem: React.FC<StoreProductItemProps> = ({ product, car
         <img src={productImageUrl(product)} alt='' />
       </div>
       <p className="name">{product.name}</p>
-      {product.amount &&
-        <div className='price'>
-          <p>{FormatLib.price(product.amount)}</p>
-          <span>/ {t('app.public.store_product_item.unit')}</span>
-        </div>
-      }
+      <div className='price'>
+        <p>{FormatLib.price(product.amount || 0)}</p>
+        <span>/ {t('app.public.store_product_item.unit')}</span>
+      </div>
       <FabStateLabel status={statusColor(product)}>
         {productStockStatus(product)}
       </FabStateLabel>
diff --git a/app/frontend/src/javascript/components/store/store-product.tsx b/app/frontend/src/javascript/components/store/store-product.tsx
index ac02b0931..4ebae268a 100644
--- a/app/frontend/src/javascript/components/store/store-product.tsx
+++ b/app/frontend/src/javascript/components/store/store-product.tsx
@@ -180,7 +180,7 @@ export const StoreProduct: React.FC<StoreProductProps> = ({ productSlug, current
             {productStockStatus(product)}
           </FabStateLabel>
           <div className='price'>
-            <p>{FormatLib.price(product.amount)} <sup>TTC</sup></p>
+            <p>{FormatLib.price(product.amount || 0)} <sup>TTC</sup></p>
             <span>/ {t('app.public.store_product_item.unit')}</span>
           </div>
           {product.stock.external > (product.quantity_min || 1) &&
diff --git a/app/models/product.rb b/app/models/product.rb
index 682a3f8fe..37f5d1a04 100644
--- a/app/models/product.rb
+++ b/app/models/product.rb
@@ -20,7 +20,8 @@ class Product < ApplicationRecord
   accepts_nested_attributes_for :product_stock_movements, allow_destroy: true, reject_if: :all_blank
 
   validates :name, :slug, presence: true
-  validates :amount, numericality: { greater_than: 0, allow_nil: true }
+  validates :slug, uniqueness: true
+  validates :amount, numericality: { greater_than_or_equal_to: 0, allow_nil: true }
 
   scope :active, -> { where(is_active: true) }
 
diff --git a/app/models/product_category.rb b/app/models/product_category.rb
index 40af30a1a..afe4595ae 100644
--- a/app/models/product_category.rb
+++ b/app/models/product_category.rb
@@ -7,6 +7,7 @@ class ProductCategory < ApplicationRecord
   friendly_id :name, use: :slugged
 
   validates :name, :slug, presence: true
+  validates :slug, uniqueness: true
 
   belongs_to :parent, class_name: 'ProductCategory'
   has_many :children, class_name: 'ProductCategory', foreign_key: :parent_id
diff --git a/app/services/cart/add_item_service.rb b/app/services/cart/add_item_service.rb
index 31477a180..4fbc4ea3a 100644
--- a/app/services/cart/add_item_service.rb
+++ b/app/services/cart/add_item_service.rb
@@ -11,7 +11,7 @@ class Cart::AddItemService
     quantity = orderable.quantity_min > quantity.to_i && item.nil? ? orderable.quantity_min : quantity.to_i
 
     if item.nil?
-      item = order.order_items.new(quantity: quantity, orderable: orderable, amount: orderable.amount)
+      item = order.order_items.new(quantity: quantity, orderable: orderable, amount: orderable.amount || 0)
     else
       item.quantity += quantity.to_i
     end
diff --git a/app/services/checkout/payment_service.rb b/app/services/checkout/payment_service.rb
index 470086f9b..429870e5f 100644
--- a/app/services/checkout/payment_service.rb
+++ b/app/services/checkout/payment_service.rb
@@ -7,9 +7,13 @@ class Checkout::PaymentService
   include Payments::PaymentConcern
 
   def payment(order, operator, coupon_code, payment_id = '')
+    raise Cart::InactiveProductError unless Orders::OrderService.new.all_products_is_active?(order)
+
     raise Cart::OutStockError unless Orders::OrderService.new.in_stock?(order, 'external')
 
-    raise Cart::InactiveProductError unless Orders::OrderService.new.all_products_is_active?(order)
+    raise Cart::QuantityMinError unless Orders::OrderService.new.greater_than_quantity_min?(order)
+
+    raise Cart::ItemAmountError unless Orders::OrderService.new.item_amount_not_equal?(order)
 
     CouponService.new.validate(coupon_code, order.statistic_profile.user.id)
 
diff --git a/app/services/orders/order_service.rb b/app/services/orders/order_service.rb
index 622acade9..4b1209131 100644
--- a/app/services/orders/order_service.rb
+++ b/app/services/orders/order_service.rb
@@ -58,6 +58,20 @@ class Orders::OrderService
     true
   end
 
+  def greater_than_quantity_min?(order)
+    order.order_items.each do |item|
+      return false if item.quantity < item.orderable.quantity_min
+    end
+    true
+  end
+
+  def item_amount_not_equal?(order)
+    order.order_items.each do |item|
+      return false if item.amount != item.orderable.amount
+    end
+    true
+  end
+
   def all_products_is_active?(order)
     order.order_items.each do |item|
       return false unless item.orderable.is_active
diff --git a/app/services/product_service.rb b/app/services/product_service.rb
index 38db4eefb..ff7f8432e 100644
--- a/app/services/product_service.rb
+++ b/app/services/product_service.rb
@@ -55,7 +55,8 @@ class ProductService
     def create(product_params, stock_movement_params = [])
       product = Product.new(product_params)
       product.amount = amount_multiplied_by_hundred(product_params[:amount])
-      update(product, product_params, stock_movement_params)
+      update_stock(product, stock_movement_params)
+      product
     end
 
     def update(product, product_params, stock_movement_params = [])
@@ -64,5 +65,20 @@ class ProductService
       update_stock(product, stock_movement_params)
       product
     end
+
+    def destroy(product)
+      used_in_order = OrderItem.joins(:order).where.not('orders.state' => 'cart')
+                               .exists?(orderable: product)
+      raise CannotDeleteProductError if used_in_order
+
+      ActiveRecord::Base.transaction do
+        orders_with_product = Order.joins(:order_items).where(state: 'cart').where('order_items.orderable': product)
+        orders_with_product.each do |order|
+          ::Cart::RemoveItemService.new.call(order, product)
+        end
+
+        product.destroy
+      end
+    end
   end
 end