BOE 76 of March 27, 2018.Resolution of March 27, 2018, jointly of the General Secretariat of the Treasury and Financial Policy and the General Intervention of the State Administration, which regulates the procedure for making the payment of contributions in favor of the General Treasury of Social Security
Last January, the General Treasury of Social Security issued the resolution provided for in said second final provision for the application of the direct settlement system to the ministerial departments, which will be applied on a mandatory basis for the determination and payment of the contributions of the Social Security from the third calendar month following the one in which the incorporation took place. Therefore, it will be mandatory as of May 1, 2018, unless you choose to apply it earlier.
The new system for direct settlement of fees constitutes a modification that affects both the processes associated with its calculation and transmission, as well as the treatment and control of collection and the monitoring of collections and debt.
Source: BOE 76 of March 27, 2018
