First, adjustments in the income tax structure. Higher income earners would bear the cost in form of a solidarity levy to finance the benefit to the poor.
Second, the NAMTAX consortium proposed to fund the BIG through an increase of 6.5% in VAT. This would entail that people would pay more for their daily goods but at the same time would also benefit from the BIG. The model prepared by the consortium shows that 85% of the people would benefit more from the BIG than paying more on daily goods. The increase in VAT would finance the BIG by making rich people pay for it, hence it would distribute income more fairly in society. In addition, one can think of other funding methods, like increasing taxes on luxury goods like cars, tobacco, alcohol etc.
Third, through reprioritization in the budget.