Each financial transaction is recorded in at least two different nominal ledger accounts within the financial accounting system, so that the total debits equals the total credits in the general ledger, i.e. the accounts balance. This is a partial check that each and every transaction has been correctly recorded. The transaction is recorded as a “debit entry” (Dr) in one account, and a “credit entry” (Cr) in a second account. The debit entry will be recorded on the debit side (left-hand side) of a general ledger account, and the credit entry will be recorded on the credit side (right-hand side) of a general ledger account. If the total of the entries on the debit side of one account is greater than the total on the credit side of the same nominal account, that account is said to have a debit balance.
Double entry is used only in nominal ledgers. It is not used in daybooks (journals), which normally do not form part of the nominal ledger system. The information from the daybooks will be used in the nominal ledger and it is the nominal ledgers that will ensure the integrity of the resulting financial information created from the daybooks (provided that the information recorded in the daybooks is correct).
The reason for this is to limit the number of entries in the nominal ledger: entries in the daybooks can be totalled before they are entered in the nominal ledger. If there are only a relatively small number of transactions it may be simpler instead to treat the daybooks as an integral part of the nominal ledger and thus of the double-entry system.
However, as can be seen from the examples of daybooks shown below, it is still necessary to check, within each daybook, that the postings from the daybook balance.
The double entry system uses nominal ledger accounts. From these nominal ledger accounts a trial balance can be created. The trial balance lists all the nominal ledger account balances. The list is split into two columns, with debit balances placed in the left hand column and credit balances placed in the right hand column. Another column will contain the name of the nominal ledger account describing what each value is for. The total of the debit column must equal the total of the credit column.