Final answer:
Postings to control accounts in a costing system are made to consolidate and summarize transaction details from subsidiary ledgers, which helps in maintaining organized accounts and providing a clear financial overview.
Step-by-step explanation:
Postings to control accounts in a costing system are made to summarize the totals of individual transactions that relate to a certain general ledger account. Control accounts are used in conjunction with subsidiary ledgers, allowing for a more streamlined and organized accounting process. For example, a company may have an accounts payable control account that consolidates all the amounts owed to suppliers, with the details of each individual supplier's balance kept in a subsidiary ledger.
In managerial accounting, control accounts are a fundamental component of an internal financial reporting system, which aids in checking the accuracy of financial records and providing a quick overview of an entity's financial standing without having to delve into the details of every single transaction. This allows for both effective management of different business transactions and the ability to detect discrepancies or errors quickly.