diff --git a/addons/sale/sale.py b/addons/sale/sale.py
index 2fa632ef8db..cc8a1606102 100644
--- a/addons/sale/sale.py
+++ b/addons/sale/sale.py
@@ -605,7 +605,7 @@ class SaleOrderLine(models.Model):
     price_total = fields.Monetary(compute='_compute_amount', string='Total', readonly=True, store=True)
 
     price_reduce = fields.Monetary(compute='_get_price_reduce', string='Price Reduce', readonly=True, store=True)
-    tax_id = fields.Many2many('account.tax', string='Taxes', readonly=True, states={'draft': [('readonly', False)]})
+    tax_id = fields.Many2many('account.tax', string='Taxes')
 
     discount = fields.Float(string='Discount (%)', digits_compute=dp.get_precision('Discount'), default=0.0)
 
diff --git a/addons/sale/sale_view.xml b/addons/sale/sale_view.xml
index d7b2ca776ee..60649e75dd6 100644
--- a/addons/sale/sale_view.xml
+++ b/addons/sale/sale_view.xml
@@ -186,7 +186,7 @@
                                         <group>
                                             <field name="product_id"
                                                 context="{'partner_id':parent.partner_id, 'quantity':product_uom_qty, 'pricelist':parent.pricelist_id, 'uom':product_uom, 'company_id': parent.company_id}"
-                                                attrs="{'readonly': [('state', 'in', ('sale','done', 'cancel'))]}"
+                                                attrs="{'readonly': [('qty_invoiced', '&gt;', 0)]}"
                                                />
                                             <field name="invoice_status" invisible="1"/>
                                             <field name="qty_to_invoice" invisible="1"/>
@@ -216,7 +216,8 @@
                                             </div>
                                         </group>
                                         <group>
-                                            <field name="tax_id" widget="many2many_tags" domain="[('type_tax_use','=','sale'),('company_id','=',parent.company_id)]"/>
+                                            <field name="tax_id" widget="many2many_tags" domain="[('type_tax_use','=','sale'),('company_id','=',parent.company_id)]"
+                                                attrs="{'readonly': [('qty_invoiced', '&gt;', 0)]}"/>
                                             <label for="customer_lead"/>
                                             <div>
                                                 <field name="customer_lead" class="oe_inline"/> days
@@ -234,7 +235,7 @@
                                 <tree string="Sales Order Lines" editable="bottom" decoration-info="invoice_status=='to invoice'">
                                     <field name="sequence" widget="handle"/>
                                     <field name="product_id"
-                                        attrs="{'readonly': [('state', 'in', ('sale','done', 'cancel'))]}"
+                                        attrs="{'readonly': [('qty_invoiced', '&gt;', 0)]}"
                                         context="{'partner_id':parent.partner_id, 'quantity':product_uom_qty, 'pricelist':parent.pricelist_id, 'uom':product_uom, 'company_id': parent.company_id}"
                                        />
                                     <field name="name"/>
@@ -253,7 +254,8 @@
                                         groups="product.group_uom" options='{"no_open": True}'/>
                                     <field name="price_unit"
                                         attrs="{'readonly': [('qty_invoiced', '&gt;', 0)]}"/>
-                                    <field name="tax_id" widget="many2many_tags" domain="[('type_tax_use','=','sale'),('company_id','=',parent.company_id)]"/>
+                                    <field name="tax_id" widget="many2many_tags" domain="[('type_tax_use','=','sale'),('company_id','=',parent.company_id)]"
+                                        attrs="{'readonly': [('qty_invoiced', '&gt;', 0)]}"/>
                                     <field name="discount" groups="sale.group_discount_per_so_line"/>
                                     <field name="price_subtotal" widget="monetary"/>
                                     <field name="qty_delivered_updateable" invisible="1"/>