All costs incurred for the preparation and submission of tenders are to be borne by the  tenderers and will not be reimbursed. This invitation to tender is in no way binding on the contracting authority. The contracting  authority's contractual obligation commences only when the contract with the successful  tenderer is signed by both parties.  Up to the signature of the contract the contracting authority may cancel the procurement  procedure without tenderers being entitled to claim any compensation. Any such decision  must be substantiated and tenderers notified.  The validity period of the tender, during which tenderers may not modify the terms of their  tenders in any respect, is indicated under Heading IV.2.6 of the contract notice. Submission of a tender implies acceptance of all the terms and conditions set out in the  procurement documents and, where appropriate, waiver of the tenderer's own general or  specific terms and conditions. The submitted tender is binding on the tenderer to whom the  contract is awarded for the duration of the contract.  Contacts between the contracting authority and tenderers are prohibited throughout the  procedure save in exceptional circumstances and under the following conditions only:  Upon request, the contracting authority may provide additional information solely for the  purpose of clarifying the procurement documents.  Any request for additional information must be made in writing only through the above TED  e-Tendering website in the "Questions & answers" tab, by clicking "Create a question"  (registration on TED e-Tendering is required to be able to create and submit a question).  The contracting authority is not bound to reply to requests for additional information received  less than six working$^{5}$ days before the time-limit for receipt of tenders. The contracting authority may, on its own initiative, inform interested parties of any error,  inaccuracy, omission or any other type of clerical error in the text of the procurement  documents.  Any additional information will be published on the above TED e-Tendering website. The  website will be updated regularly and it is the tenderer's responsibility to check for updates  and modifications during the submission period.  Tenders will be opened in public at the time and place indicated under Heading IV.2.7 of the  contract notice. A maximum of one representative per tender may attend the opening session.  $^{5}$ Working days at the contracting authority's location indicated under Heading I.1 of the contract notice. 3  2. Legal effects of the invitation to tender and submission of a tender.  3. Contacts during the procurement procedure.  3.1 Submission phase (before the time-limit for receipt of tenders)  3.2 Opening of tenders 