diff --git a/models/booking_event_registration.py b/models/booking_event_registration.py
index 107508c..89205e8 100644
--- a/models/booking_event_registration.py
+++ b/models/booking_event_registration.py
@@ -208,32 +208,70 @@ class EventRegistration(models.Model):
         if invoice:
             if invoice.payment_state!='paid':
                 invoice.state='draft'
+                invoice.posted_before=False
                 invoice_id=self.invoice_id
                 self.invoice_id=False
+
+                #suppression des  lignes de paiements liés à la facture
+                move_line=self.env['account.move.line'].sudo().search([('move_id','=',int(invoice_id))])
+                if move_line:
+                    for m in move_line:
+                        self.env['account.payment.line'].sudo().search([('move_line_id','=',int(m.id))]).unlink()
+
                  #suppression des paiements liés à la facture
                 self.env['account.payment'].sudo().search([('move_id','=',int(invoice_id))]).unlink()
 
                 #suppression des écritures comptables lié à la facture
                 self.env['account.move.line'].sudo().search([('move_id','=',int(invoice_id))]).unlink()
                 #suppression de la facture
+                
                 self.env['account.move'].sudo().search([('id','=',int(invoice_id))]).unlink()
         
-        invoice=self.env['account.move'].sudo().search([('id','=',int(self.down_payment_invoice_id))])
-        if invoice:
-            if invoice.payment_state!='paid':
-                invoice.state='draft'
-                invoice_id=self.down_payment_invoice_id
-                self.down_payment_invoice_id=False
-                self.env['account.move'].sudo().search([('id','=',int(invoice_id))]).unlink()
-        
-        invoice=self.env['account.move'].sudo().search([('id','=',int(self.balance_invoice_id))])
-        if invoice:
+        if self.down_payment_invoice_id:
+            invoice=self.env['account.move'].sudo().search([('id','=',int(self.down_payment_invoice_id))])
+            if invoice:
                 if invoice.payment_state!='paid':
                     invoice.state='draft'
-                    invoice_id=self.balance_invoice_id
-                    self.balance_invoice_id=False
+                    invoice.posted_before=False
+                    invoice_id=self.down_payment_invoice_id
+                    self.down_payment_invoice_id=False
+                    #suppression des  lignes de paiements liés à la facture
+                    move_line=self.env['account.move.line'].sudo().search([('move_id','=',int(invoice_id))])
+                    if move_line:
+                        for m in move_line:
+                            self.env['account.payment.line'].sudo().search([('move_line_id','=',int(m.id))]).unlink()
+
+                    #suppression des paiements liés à la facture
+                    self.env['account.payment'].sudo().search([('move_id','=',int(invoice_id))]).unlink()
+
+                    #suppression des écritures comptables lié à la facture
+                    self.env['account.move.line'].sudo().search([('move_id','=',int(invoice_id))]).unlink()
+                    #suppression de la facture
+                    
                     self.env['account.move'].sudo().search([('id','=',int(invoice_id))]).unlink()
-            
+        if self.balance_invoice_id:
+            invoice=self.env['account.move'].sudo().search([('id','=',int(self.balance_invoice_id))])
+            if invoice:
+                    if invoice.payment_state!='paid':
+                        invoice.state='draft'
+                        invoice.posted_before=False
+                        invoice_id=self.balance_invoice_id
+                        self.balance_invoice_id=False
+                        #suppression des  lignes de paiements liés à la facture
+                        move_line=self.env['account.move.line'].sudo().search([('move_id','=',int(invoice_id))])
+                        if move_line:
+                            for m in move_line:
+                                self.env['account.payment.line'].sudo().search([('move_line_id','=',int(m.id))]).unlink()
+
+                        #suppression des paiements liés à la facture
+                        self.env['account.payment'].sudo().search([('move_id','=',int(invoice_id))]).unlink()
+
+                        #suppression des écritures comptables lié à la facture
+                        self.env['account.move.line'].sudo().search([('move_id','=',int(invoice_id))]).unlink()
+                        #suppression de la facture
+                        
+                        self.env['account.move'].sudo().search([('id','=',int(invoice_id))]).unlink()
+                    
      
         return True