diff --git a/netforce_clinic/layouts/clinic_hd_case_form.xml b/netforce_clinic/layouts/clinic_hd_case_form.xml
index 17d8705..42e9eed 100644
--- a/netforce_clinic/layouts/clinic_hd_case_form.xml
+++ b/netforce_clinic/layouts/clinic_hd_case_form.xml
@@ -136,6 +136,7 @@
             <head>
                 <button string="Print" action="clinic_hdcase_invoice_print" action_options="convert=pdf" icon="print"/>
                 <button string="Pay" method="pay_invoice" type="success"/>
+                <button string="To Draft" method="hdcase_to_draft" type="default"/>
             </head>
                 <field name="number"/>
                 <field name="ref"/>
diff --git a/netforce_clinic/models/account_invoice.py b/netforce_clinic/models/account_invoice.py
index db919f5..c5200d0 100644
--- a/netforce_clinic/models/account_invoice.py
+++ b/netforce_clinic/models/account_invoice.py
@@ -469,5 +469,15 @@ class AccountInvoice(Model):
             'flash': 'Invoice: %s has been paid'%(','.join(paid_inv)),
         }
 
+    def hdcase_to_draft(self, ids, context={}):
+        for payment_line in get_model("account.payment.line").search_browse([['invoice_id','in',ids]]):
+            payment=payment_line.payment_id
+            rel=payment.related_id
+            if rel._model=='clinic.hd.case':
+                payment.to_draft()
+                payment.delete()
+        for inv in self.browse(ids):
+            inv.to_draft()
+            inv.approve()
 
 AccountInvoice.register()
