There are certain accounting errors that do not affect an accounting trial balance, including:
Error of total omission
This occurs when an accounting entry is completely omitted from the book of accounts. In such a case, the trial balance totals will still balance as no entry was ever made.
Original entry error
This occurs when the original entry was either overstated or understated by a certain amount. For instance, original purchases might be $200, but the accountant mistakes it for $100. The accountant then debits the purchases ledger account with $100 and credits the cash account or the creditors account with $100. This error will not affect the trial balance.
These are multiple accounting errors that may individually affect the trial balance, but since they are multiple accounts, they end up canceling each other out and thus do not affect the totals of the trial balance.
This is an accounting error that occurs when the correct amounts are entered in the debit side instead of the credit side. This does not affect the trial balance.
This error is caused when two adjacent digits are switched. The trail balance will still balance but the balancing amount would be wrong.
Error of principle
This accounting error occurs when the amount is entered correctly but is entered in the wrong account. This error will not affect the accounting trial balance.
These are some of the accounting errors that do not affect the accounting trial balance. Sometimes these errors may never be discovered.
There is a plethora of information on the web regarding Accounting errors that do not affect the trial balance. They have a good resources section and are helpful for both small businesses looking for a qualified certified public accountant AND CPAs looking for help with marketing. Their research service is free for small businesses looking for help with their accounting. The IRS website is also helpful but a little more technical.