The most common control accounts are the accounts receivable and accounts payable control accounts. For companies that have a lot of customers, give prompt payment discounts, have returns of goods and record thousands of transactions, a control is account is very useful. It’s basically an additional layer to check the accuracy of the subledgers.
Each customer will have a unique subledger but how do you know if all transactions are recorded properly? The control account is used to summarise all the transactions while eliminating the details that are now useful for financial reporting (customer details etc). If the control account does not match the subledgers, then it becomes easier to identify where the error comes from (which subledger).