In the example above, USD 1,400 (3,000 CNOL carried over to year 4, 1,600 CNOL used to compensate for the group`s taxable year 4) of the CNOL at the end of the 4th year. If the remaining loss is attributable to a member who then leaves the group, several complex questions arise. While an in-depth discussion of these issues goes beyond the scope of this section, you should consider the following circumstances: If a parent company sells a subsidiary`s stock at a loss and the member is deconsolidated, the consolidated refund rules may allow the superior entity to reassign some of the member`s tax attributes. [See section 1.1502-36 of Treasury Regulations; see also Internal Income Code (IRC) Section 108 and Treasury Regulations section 1.1502-28.] This allows the parent company to retain the outgoing member`s tax attributes and prevents that member from using these attributes in subsequent separate return years. To avoid this, a buyer may require, prior to the closing of the transaction, that the group`s tax allowance agreement be amended to contain a language that expressly prohibits the parent from reallocating a member`s tax attributes. This amended and amended agreement will come into effect on November 21, 2013 by and between Ameren Corporation, a Missouri company, and its related companies, as shown in Figure A (together the “group”; individually “group member”). In the absence of a binding agreement, members are not required to pay the parent for their share of the group`s tax debt and the parent is not required to compensate members for the use of their tax attributes. To ensure that members receive adequate compensation for the group`s use of their tax attributes and that their assets are not depleted by excessive taxes paid to the parent company, many tax advisors recommend that groups sign legally binding tax allocation agreements that define how cash payments and refunds are made between members.