23- received and the amounts withheld, in order that the employer can prepare the annual tax return. No later than January 31, the name of the employer who will prepare the annual return must he furnished to the other employers so they will not also prepare such return. Balances of taxes due under either of the two procedures above must be paid in the month of April of the following year or in nine monthly payments, the first of which is due in April. When the payments are to be made in installments, the employer who pays the highest amount of salary to the employee must withhold such install-ments. 39. Income for periods less _than a year:_ The employer no longer has the obligation to calculate the tax on the proportional annual income when the income received is for periods less than a year. 40. Indemnities: Discharge indemnities are not includable in annual taxable income, The applicable tax, which in this case is final, is computed based on the rate table for provisional payments (see Exhibit C) which is applied to the latest regular monthly salary; the amount resulting from applying such rate is multiplied by the quotient obtained by dividing the amount of the indemnity by the latest regular monthly salary; the product is the tax to be withheld. ii. Exercise of a professional or technical activity, etc.- 41. Taxable income: The taxable income is the net income obtained by the profes-sional, artisan, technician, etc. during a calendar year, less an ad-justment of 20% of such income; this adjustment cannot exceed US$2,400.. Net income is determined by deducting from the gross income received by the taxpayers the percentages of depreciation and amortiza- tion established for business enterprises, as well as the normal and proper expenses relating to the exercise of the profession or activity, provided that the tax requirements established for deductions made by business enterprises are met. Those who do not wish to prove their deductions can, as an alternative, deduct 20% of gross income received.