Contract number: [ complete ]  Service contract conditions of December 2018  b) a positive and related order confirmation message has been successfully sent from the  contractor  to the  contracting authority  (equivalent to the  contractor  's signature) ;  and  c) a final message endorsing the order has been sent by the  contracting authority  to the  contractor  and successfully received by him (equivalent to the  contracting authority 's  signature).  a) In case of using  web services , when its status is set to "received" as defined in the  interface control document.  b) In case of using the  supplier portal , when the contractor is able to successfully submit  the e-document without any error messages. The XML document related to the e- document is considered as a proof of receipt by the  contracting authority. 6.4. A  dispatch advice ,  invoice or debit/credit note shall be deemed to have been legally  issued or sent:  6.5. A  request for quotation  or a  receipt advice is deemed to have been legally sent by the  contracting authority  when the message has been successfully received by the  contractor .  To the extent permitted by the applicable law, the parties hereby agree that in the event of  dispute, the electronic documents (including, in the case of using the  web services , the records  of the  EDI messages maintained in accordance with the terms and conditions of this  agreement) shall be admissible before the courts and shall constitute evidence of the facts  contained therein unless evidence to the contrary is adduced.  8.1  When using  web services  all  EDI messages  exchanged by the parties shall be stored by  each party, unaltered and securely, in accordance with the time limits and specifications  prescribed by the applicable legislative requirements. The parties agree that  EDI messages that have been stored may be reproduced on any type of data carrier whatsoever and may be  made legible by means of said reproduction.  8.2  When using  the  supplier portal , the contractor shall download the PDF or XML  message for each e-document within one year of submission, and store them securely. After  this period, copies of the e-documents are no longer available for automatic download from  the  supplier portal .  This agreement shall enter into force on the date of signature of the  contract  by the last party  and shall become applicable for each module from the date indicated in section 1.2 of this  agreement.  10.1. Any amendment to the agreement must be made in writing and agreed by both parties.  10.2. Amendments will be part of the present agreement from the time of their signature by  the last party.  49  10. AMENDMENTS  9. ENTRY INTO FORCE  8. STORAGE OF ELECTRONIC DOCUMENTS  7. ADMISSIBILITY