Technical assistance for the IT development of corrections and enhancements to the Integrated Tax System (ITS) on behalf of the Directorate General of Taxes, divided into two separate lots: • Lot no. 1: technical assistance for the IT development of corrections and enhancements to the functional area "Assessment and Control" of the Integrated Tax System (ITS). • Lot no. 2: technical assistance for the IT development of corrections and enhancements to the functional area "Collection, Litigation and Accounting" of the Integrated Tax System (ITS).