Contract number: EEAS-618-DELBRBB-SER-FWC-2019   Template of June 2018 Updated November 2018  (b) by calling in a financial guarantee if the contractor has submitted one to the  contracting authority; (c) by taking legal action. II.23.3. Interest on late payment  II.23.4. Recovery rules in the case of joint tender  II.24. CHECKS AND AUDITS  If the contractor does not honour the obligation to pay the amount due by the date set by the  contracting authority in the debit note, the amount due bears interest at the rate indicated in  Article II.21.8. Interest on late payments will cover the period starting on the day after the due  date for payment and ending on the date when the contracting authority receives the full  amount owed. Any partial payment is first entered against charges and interest on late payment and then  against the principal amount.  If the contract is signed by a group (joint tender), the group is jointly and severally liable  under the conditions set out in Article II.6 (liability). The contracting authority first claims the  full amount to the leader of the group. If the leader does not pay by the due date and if the amount cannot be offset in accordance  with Article II.23.2 (a), the contracting authority may claim the full amount to any other  member of the group by  notifying the debit note already sent to the leader under  Article II.23.2. Such checks and audits may be initiated at any moment during the provision of the  services and up to five years starting from the payment of the balance of the last  specific contract issued under this FWC The audit procedure is initiated on the date of receipt of the relevant letter sent by the  contracting authority. Audits are carried out on a confidential basis.  II.24.1 The contracting authority and the European Anti-Fraud Office may check or require  an audit on the  implementation of the FWC . This may be carried out either by  OLAF’s own staff or by any outside body authorised to do so on its behalf. II.24.2 The contractor must keep all original documents stored on any appropriate medium,  including digitised originals if authorised under national law, for a period of five  years starting from the payment of the balance of the last specific contract issued  under this FWC II.24.3 The contractor must grant the contracting authority’s staff and outside personnel  authorised by the contracting authority the appropriate right of access to sites and  premises where the FWC is implemented and to all the information, including  information in electronic format, needed to conduct such checks and audits. The  contractor must ensure that the information is readily available at the moment of the  37 