subsidiary ledger
/ sub-SID-ee-air-ee LEJ-er /
Suppose a company is owed money by 300 different customers. If the general ledger held one line per customer, it would become an unreadable wall of detail. Instead, the main books keep a single summary figure, and the customer-by-customer breakdown lives in a separate book of its own. That separate book of detail is a subsidiary ledger.
A subsidiary ledger contains the individual accounts that make up one summary account in the general ledger. The most common are the accounts receivable subsidiary ledger (one account per customer) and the accounts payable subsidiary ledger (one account per supplier). The key rule: the total of all the individual accounts in the subsidiary ledger must equal the balance of the matching summary account in the general ledger. If the receivable subledger lists customers owing $4,000, $7,000, and $1,000, the general ledger's Accounts Receivable should read $12,000.
Subsidiary ledgers matter because they give detail without cluttering the main books, and they let different people work on different parts at once. They pair with a 'control account' in the general ledger, which holds the matching total. A frequent point of confusion: the subsidiary ledger is not part of the formal trial balance — only the control account total appears there; the subledger sits behind it, available when you need the detail.
The accounts receivable subsidiary ledger shows Customer A owes $4,000, Customer B $7,000, and Customer C $1,000. These add to $12,000, which must equal the single Accounts Receivable balance shown in the general ledger.
Customer detail summing to the single general-ledger total.
A subsidiary ledger does not appear on the trial balance — only its control-account total does; the two must always agree, and a mismatch signals an error to track down.