African Union Legal Instrument P a g e | 12 In addition to the type of controls described in § 1, the following methods are examples of technologies that ensure the authenticity of origin and integrity of content of an electronic invoice: 6. a) a qualified electronic signature as defined in Article 1; b) electronic data interchange (EDI), understood as the electronic transfer, from computer to computer, of commercial and administrative data in the form of an EDI message structured according to an agreed standard, provided that the agreement to the exchange provides for the use of procedures guaranteeing the authenticity of the origin and data integrity. A written document in electronic form is admissible in evidence in the same way as a paper-based document, and shall have the same force of law, provided that the person from whom it originates can be duly identified and that it has been made out and retained in a manner that guarantees its integrity. Section III: Security of Electronic Transactions Article 7: Ensuring the Security of Electronic Transactions 1. a) The supplier of goods shall allow his/her clients to make payments using electronic payment methods approved by the State according to the regulations in force in each State Party. b) The supplier of goods or provider of services by electronic means who claims the discharge of an obligation must prove its existence or otherwise prove that the obligation was discharged or did not exist. 2. Where the legislative provisions of State Parties have not laid down other principles, and where there is no valid agreement between the parties, the judge shall resolve proof related conflicts by determining by all possible means the most plausible claim regardless of the message base employed. 3. a) A copy or any other reproduction of contracts signed by electronic means shall have the same probative value as the contract itself, where the said copy has been certified as a true copy of the said act by bodies duly accredited by an authority of the State Party. b) Certification will result in the issuance, where necessary, of a certificate of conformity.