ECOWAS Tenders Code 2. The securities provided for under Part III, Chapter II of this Code may be replaced by a joint and several guarantor whereby a third party undertakes to pay to the procuring entity any sums owed by the supplier, contractor or service provider in respect of the contract up to the amount posted as guarantee. 3. The joint and several guarantor shall be chosen from approved reputable banks / insurance companies. 4. The joint and several guarantee shall be in a format specified by the procuring entity. The form shall contain an undertaking to pay on first demand, any amount owed by the contractor up to the amount guaranteed. Article 70: Other Securities 1. Where the contract provides for advance payment, the supplier, contractor or service provider, shall provide a security for the repayment of the advance payments. Advance payment shall not exceed thirty (30) percent of the contract price. 2. If the contractor receives advance payments for the purchase of materials or goods, the ownership of these materials is transferred to the procuring entity. The contractor shall be legally responsible for the care of these materials. 3. Where the contract specifies a warranty period, a portion of each payment shall be retained by the procuring entity as retention guarantee in order to secure the full compliance with the contract obligations. The sum retained by the procuring entity as determined by the Contracting Authority, which may be replaced by a joint and several guarantee, should not exceed ten (10) percent of the total amount of the payments and shall be specified in the conditions of contract depending on the contract value and risks. In any case , the retention guarantee shall be entirely returned at the expiry of the guarantee period. This period is the period during which the work is accepted and the facility utilized during which any defects discovered shall be rectified by the contractor at no liability to the contractor. The duration of the guarantee period shall be fixed in the contract. 4. The contract shall determine, where necessary, any guarantees other than those stipulated above which may, under special circumstances, be required of the supplier or contractor to ensure the discharge of his obligations. The contract shall define the rights of the procuring entity in relation to such guarantees. Chapter III: Modifications during the Execution of the Contract Article 71: Modification in the Contract Quantities or Price 1. Any variations to the initial contract shall be embodied in an amendment to the contract except in the cases specified in paragraphs (a) and (c) of this Article. a) Variations in the execution of contracts for works, supplies or services not exceeding ten percent (10%) of the total value of the contract shall be verified and approved by an order issued by the procuring entity. Final Page 33