Prohibition on Amending the Contract and Concluding a Supplementary Contract

Other than in the cases specified in Public Procurement Contracts Law No. 4735, the terms of a contract may not be amended and no supplementary contract may be drawn up once the contract has been concluded, under Article 4 of that Law. The Law permits the place of performance or delivery of the work, and the period of the work and the payment conditions corresponding to that period, to be changed after the contract is signed, provided the work is performed or delivered early, under Article 15 of Law No. 4735.