General-ledger summary account whose balance should agree with the detail total in its related subsidiary ledger.
A control account is a general-ledger account that summarizes the total of a related subsidiary ledger. It lets accountants keep detail records in one place while preserving a concise summary in the general ledger.
Control accounts are central to reconciliation and internal control. If the control-account balance does not match the related subsidiary-ledger total, the difference usually signals a posting error, omission, or timing problem that needs investigation.
Accounts receivable, accounts payable, and inventory are common examples. The subsidiary ledger holds the detail by customer, vendor, or item. The control account in the general ledger carries only the summarized total.
At period end, accountants compare the detailed ledger total with the control account. That comparison supports the trial balance and helps prove that the general-ledger amount is reliable.
If the accounts payable subsidiary ledger totals 83,400 across all vendors, the accounts payable control account in the general ledger should also show 83,400. Any difference means the detail and summary records are out of sync.
A control account is not the same thing as the subsidiary ledger itself. The control account is the summary. The subsidiary ledger is the detailed support.