In the year 2005 the World Bank proposed to design an economic benefit for every citizen depending on his own situation. This kind of benefit has to be supported in an annual financial base, taking into accounts the demographic and economic situation of the country. It is possible to define this benefit as Basic Income. This new level of social protection implies a redesign of the basic and compulsory level of protection that every country has. Even more, it implies re-designing the whole system of benefits, because part of them should include a Basic Income. This step is necessary, since for definition the Basic Income benefit is universal, individual and unconditional  one and all the citizens will receive it, having salaries or not.

In Spain the financial model for the Social Security is a pay as you go and there is a high number of different grants that would be included partially inside this conception.

The aim of this paper is to design an actuarial model for financing the Basic Income Benefit. This model has to redistribute the existing benefits (retirement, disability, mortality) and the Basic Income benefit. The model, as well as, has to redirect the sufficient income to finance them, without reducing the technical balance of the Social Security system.

This conception implies to modify the actuarial model in use for the nowadays Social Security system to a new one based on the International Labor Office model –ILO 1998-.