Which of the following is a primary source of entry into the debtors ledger?

The debtors ledger (also called the sales ledger) contains the individual accounts of customers who owe the business money for goods bought on credit. Entries in this ledger must originate from documents that record credit sales transactions.

A sales invoice is issued by the business to a customer at the point a credit sale is made, and it states what the customer owes; this is the primary source document used to post amounts owed into the customer's individual account in the debtors ledger. Suppliers' invoices, by contrast, are received from suppliers when the business itself buys on credit, and they are posted to the creditors (purchases) ledger, not the debtors ledger. Payment vouchers evidence cash payments made by the business, and returns outward notes record goods the business sends back to its own suppliers, both of these relate to purchases and payments, not to sales made to customers.

Because it is the document that evidences the credit sale creating the debt in the first place, the sales invoice is the primary source of entry into the debtors ledger.

Examination tip: match each source document to the ledger it feeds; sales invoices and credit notes to customers feed the debtors ledger, while suppliers' invoices and returns outward notes feed the creditors ledger.