(a) In general—(1) Requirement of return. Except as provided in paragraphs (e) and (g)(1) of this section with respect to charitable and other organizations having unrelated business income and to certain foreign corporations, respectively, every corporation, as defined in section 7701(a)(3), subject to taxation under subtitle A of the Code shall make a return of income regardless of whether it has taxable income or regardless of the amount of its gross income. (a) For estates and trusts—(1) In general. Every fiduciary, or at least one of joint fiduciaries, must make a return of income on form 1041 (or by use of a composite return pursuant to §1.6012–5) and attach the required form if the estate or trust has items of tax preference (as defined in section 57 and the regulations thereunder) in any amount: