Bookkeeping

Single Entry Bookkeeping

Most of financial accounting is based on double-entry bookkeeping. To understand and appreciate the advantages of double entry, it is worthwhile to examine the simpler single-entry bookkeeping system. In its most basic form, a single-entry system is similar to a checkbook register and is characterized by the fact that there is only a single line entered in the journal for each transaction. In a simple checkbook, each transaction is recorded in one column of an account as either a positive or a negative amount in order to represent the receipt or disbursement of cash. This system is demonstrated in the following example for a repair shop business:

Single Column System

Date	Description	Amount
Jan 1	Beginning Balance	1,000.00
Jan 2	Purchased shop supplies	(150.00)
Jan 4	Performed repair service	275.00
Jan 7	Performed repair service	125.00
Jan 15	Paid phone bill	(50.00)
Jan 30	Ending balance	1,200.00

While extremely simple, because the above system uses a single column, only the difference between revenues and expenses is totaled - not the individual values of each. Knowing the individual total amounts of revenues and expenses is important to a business, for example, when formulating a budget. The revenues and expenses also are reported in the income statement. In the above example, the individual revenue and expense amounts can be determined only by sorting through the transactions and tabulating the revenue and expense totals. This process can be designed into the system by using a separate column for revenues and expenses:

Separating Revenues and Expenses

Date	Description	Revenues	Expenses
Jan 2	Purchased shop supplies		150.00
Jan 4	Performed repair service	275.00
Jan 7	Performed repair service	125.00
Jan 15	Paid phone bill		50.00
	January Totals	400.00	200.00

While the above example now uses two columns, it still is considered to be a single-entry system since only one line is used to record each transaction in the cash account. This single-entry system often is expanded to provide more useful information. For example, additional columns can be added to classify the revenues as sales and sales tax collected, and the expenses as rent, utilities, supplies, etc. Some single-entry systems may add dozens of columns for different types of revenues and expenses. Many small businesses utilize such a system. However, even with columns to classify the revenues and expenses, single-entry bookkeeping is limited in its ability to provide detailed financial information. Some disadvantages of a single-entry system include:

• Does not track asset and liability accounts such as inventory, accounts receivable and accounts payable. These must be tracked separately.
• Facilitates the calculation of income but not of financial position. There is no direct linkage between income and the balance sheet.
• Errors may go undetected and often are identified only through bank statement reconciliation.

Because of these drawbacks, a single-entry system is not practical for many organizations such as those having many thousands of transactions in a reporting period, significant assets, and external suppliers of capital. The more sophisticated double-entry bookkeeping system addresses the more demanding needs of such businesses.

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Double Entry Bookkeeping

A business transaction involves an exchange between two accounts. For example, for every asset there exists a claim on that asset, either by those who own the business or those who loan money to the business. Similarly, the sale of a product affects both the amount of cash (or cash receivable) held by the business and the inventory held.

Recognizing this fundamental dual nature of transactions, merchants in medieval Venice began using a double-entry bookkeeping system that records each transaction in the two accounts affected by the exchange. In the late 1400's, Franciscan monk and mathematician Luca Pacioli documented the procedure for double-entry bookkeeping as part of his famous Summa work, which described a significant portion of the accounting cycle. Double-entry bookkeeping spread throughout Europe and became the foundation of modern accounting.

Two notable characteristics of double-entry systems are that 1) each transaction is recorded in two accounts, and 2) each account has two columns.

In a double-entry system, two entries are made for each transaction - one entry as a debit in one account and the other entry as a credit in another account. The two entries keep the accounting equation in balance so that:

Assets    =    Liabilities   +   Owners' Equity

To illustrate, consider a repair shop with a transaction involving repair service performed on Jan 4 for a cash payment of $275.00. In a single-entry bookkeeping system, the transaction would be recorded as follows:

Single Entry Example

Date	Description	Revenues	Expenses
Jan 4	Performed repair service	275.00

In a double-entry system, the transaction would be recorded as follows:

Double Entry Example

Date	Accounts	Debit	Credit
Jan 4	Cash	275.00
	Revenue		275.00

A notation may be added to this journal entry to indicate that the revenue was from repair services.
Note that two accounts (revenue and cash) are affected by the transaction. If the customer did not pay cash but instead was extended credit, then "accounts receivable" would have been used instead of "cash."

In this system, the double entries take the form of debits and credits, with debits in the left column and credits in the right. For each debit there is an equal and opposite credit and the sum of all debits therefore must equal the sum of all credits. This principle is useful for identifying errors in the transaction recording process.

Double-entry accounting has the following advantages over single-entry:

• Accurate calculation of profit and loss in complex organizations
• Inclusion of assets and liabilities in the bookkeeping accounts.
• Preparation of financial statements directly from the accounts
• Easier detection of errors and fraud

To appreciate the importance of double-entry bookkeeping, it is interesting to note that the industrial revolution might not have been possible without it. At that time, businesses increased in size and complexity. Accurate bookkeeping was required for managers to understand the financial status of their businesses in order to keep them solvent and offer a degree of transparency to investors. While a single-entry system can be adapted by a skilled bookkeeper to meet some of these needs, only a double-entry system provides the required detail systematically and by design.