Contract number: ECHA/2020/666  The contractor (or leader in the case of a joint tender) must send an invoice in electronic  format, unless requested in paper, for the interim payment as provided for in the tender  specifications, accompanied by the following:   a list of all  pre-existing rights  to the  results  or parts of the  results  or a declaration stating  that there are no such  pre-existing rights , as provided for in Article II.13.4;  a relevant technical report or deliverable result or reference to tender specifications or  specific contract;  statements of travel expenses in accordance with Article I.5.3. 2. The contracting authority must approve any submitted documents or deliverables and  pay within 30 days from receipt of the invoice. 3. If the contracting authority has observations to make, it must send them to the  contractor (or leader in the case of a joint tender) and suspend the time limit for payment  in accordance with Article II.21.7. The contractor (or leader in case of a joint tender) has  10 [ten] working days to submit additional information or corrections or a new version of  the documents if the contracting authority requires it.  4. The contracting authority must give its approval and pay within the remainder of the  time-limit indicated in point (2.) unless it rejects partially or fully the submitted documents  or deliverables.  I.6.3. Payment of the balance  1. The contractor (or leader in the case of a joint tender) may claim the payment of the  balance in accordance with Article II.21.6. The contractor (or leader in the case of a joint tender) must send an invoice in electronic  format, unless requested in paper, for payment of the balance due under a specific  contract, as provided for in the tender specifications and accompanied by the following:  a list of all  pre-existing rights  to the  results  or parts of the  results  or a declaration stating  that there are no such  pre-existing rights , as provided for in Article II.13.4;  a relevant final technical report or deliverable or reference to tender specifications or  specific contract;  statements of travel expenses in accordance with Article I.5.3. 2. The contracting authority must approve the submitted documents or deliverables and  pay within 30 days from receipt of the invoice.  3. If the contracting authority has observations to make, it must send them to the  contractor (or leader in the case of a joint tender) and suspend the time limit for payment  in accordance with Article II.21.7. The contractor (or leader in the case of a joint tender) has 10 [ten] working days to submit  additional information or corrections or a new version of the documents if the contracting  authority requires it. 4. The contracting authority must give its approval and pay within the remainder of the  time-limit indicated in point (2.) unless it rejects partially or fully the submitted documents  or deliverables.  9 