Example. X has been a calendar year S corporation engaged in a trade or business for several years. X acquires the stock of Y, a calendar year C corporation, on April 1, 2002. On August 10, 2002, X makes an election to treat Y as a QSub. Unless otherwise specified on the election form, the election will be effective as of August 10, 2002. If specified on the election form, the election may be effective on some other date that is not more than two months and 15 days prior to August 10, 2002, and not more than 12 months after August 10, 2002.
26 C.F.R. §1.1361-3