Acceptance Tests 11.1 If the Contract provides acceptance tests for Goods and/or the result of Services after their completion and/or delivery to the Purchaser, the acceptance shall only be considered as definitive when such tests have demonstrated the compliance of the Goods and/or the result of the Services to the requirements in the Contract. 11.2 Where the Contract provides for an acceptance procedure in the presence of both parties, at the successful completion of such procedure, the Purchaser shall issue the Supplier with an acceptance certificate which shall authorise the Supplier to invoice the Purchaser for any payment due on such acceptance. 11.3 The Purchaser shall at its discretion be entitled to issue and acceptancecertificate with reserves. The Supplier shall be obliged to remedy any non-conformities within the period set out in the acceptance certificate. Any payment which would otherwise have been due on acceptance may be withheld by the Purchaser in whole or part until the non- conformities underlying the reserves have been remedied.