Undivided Account
An underwriting system in which each underwriter in the group is responsible not only for selling its alloted amount of the new issue but also for selling any excess issue not sold by the underwriting group as a whole. This is also referred to as an "Eastern account", and it is the opposite of a divided account.
Investopedia Commentary
For example, if an underwriter for an IPO is using the undivided account method and 90% of the issue is sold, all of the members of the underwriting group will have to share the excess that is not sold. To continue the example, if an underwriter was responsible for 30% of the issue and sold 25% of its allotment, it would be responsible for 30% of the leftover 10% above. Even if an underwriter sells more than its original allotment, if the full 100% of the underwriting group's allotment is not sold, that underwriter will still be responsible for the unsold amount.
Related Links
IPO Basics Tutorial
Brokerage Functions: Underwriting And Agency Roles
See also: Eating Stock, Initial Public Offering - IPO, New Issue, Underwriting
undivided account