required annual payment
(1) Amount (A) In general Except as otherwise provided in this section, the amount of any required installment shall be 25 percent of the required annual payment. (B) Required annual payment Except as otherwise provided in this subsection, the term “required annual payment” means the lesser of— (i) 100 percent of the tax shown on the return for the taxable year (or, if no return is filed, 100 percent of the tax for such year), or (ii) 100 percent of the tax shown on the return of the corporation for the preceding taxable year. Clause (ii) shall not apply if the preceding taxable year was not a taxable year of 12 months, or the corporation did not file a return for such preceding taxable year showing a liability for tax.