Double Entry

The accounting equation is the very heart of a double entry accounting system. For every change in value of one account in the Accounting Equation, there must be a balancing change in another. This concept is known as the Principle of Balance, and is of fundamental importance for understanding GnuCash and other double entry accounting systems. When you work with GnuCash, you will always be concerned with at least 2 accounts, to keep the Accounting Equation balanced.

Double entry accounting serves two purposes. The first is to create an accounting trail, money always has to come from somewhere and go to somewhere. Additionally, double entry accounting historically served to double check the math of an accountant. Because the numbers are entered into multiple accounts simultaneously, there are multiple places to check to make sure the totals match. Of course, with the advent of computers, the chances of a mathematical problem are low, but it is good to know that the concept still exists!

Double entry accounting has been around since the late 15th century, when it was described by an Italian friar, Luca Pacioli. Traditional double entry accounting involves recording each transaction in a book called a ledger, then copying each part of the transaction to separate books called journals. This method is still used in businesses today as a way to avoid entry errors and to track the source of those errors. GnuCash simplifies this traditional accounting by copying part of each transaction for you, so it may not catch some of the entry errors that would show up in traditional accounting. But it will flag transactions that are not balanced, and it will let you know when an account name is missing.