Illinois Statutes Chapter 35. Revenue § 5/803. Payment of Estimated Tax

(a) Every taxpayer other than an estate, trust, partnership, Subchapter S corporation or farmer is required to pay estimated tax for the taxable year, in such amount and with such forms as the Department shall prescribe, if the amount payable as estimated tax can reasonably be expected to be more than (i) $250 for taxable years ending before December 31, 2001, $500 for taxable years ending on or after December 31, 2001 and before December 31, 2019, and $1,000 for taxable years ending on or after December 31, 2019, or (ii) $400 for corporations.

(b) Estimated tax defined. The term “estimated tax” means the excess of:

(c) Joint payment. If they are eligible to do so for federal tax purposes, a husband and wife may pay estimated tax as if they were one taxpayer, in which case the liability with respect to the estimated tax shall be joint and several. If a joint payment is made but the husband and wife elect to determine their taxes under this Act separately, the estimated tax for such year may be treated as the estimated tax of either husband or wife, or may be divided between them, as they may elect.

(d) There shall be paid 4 equal installments of estimated tax for each taxable year, payable as follows:

(e) Farmers. An individual, having gross income from farming for the taxable year which is at least 2/3 of his total estimated gross income for such year.

(f) Application to short taxable years. The application of this section to taxable years of less than 12 months shall be in accordance with regulations prescribed by the Department.

(g) Fiscal years. In the application of this section to the case of a taxable year beginning on any date other than January 1, there shall be substituted, for the months specified in subsections (d) and (e), the months which correspond thereto.

(h) Installments paid in advance. Any installment of estimated tax may be paid before the date prescribed for its payment.

The changes in this Section made by this amendatory Act of 1985 shall apply to taxable years ending on or after January 1, 1986.