Transposition Errors
When two digits are reversed (or “transposed”), an error is created in the books. It’s a simple error but it completely throws off your accounting.
Example: “3563” instead of “5363.”
Subsidiary Entries:
This type of error occurs when transactions that aren’t recorded correctly
For example, an invoice is entered in accounts receivable as $10,000 instead of the $1000 actually owing.
Error of Omission:
An error of omission happens when you forget to enter a transaction in the books
For example, a copywriter buys a new business laptop but forgets to enter the purchase in the books.
Rounding Errors
Rounding a figure can make your accounting inaccurate and create a series of future errors. Either people or accounting software can make this mistake.
For example, 23.965 instead of 23.9646
Errors of Principle
A transaction that incorrectly uses an accounting principle is called an error of principle. Errors of principle don’t meet the generally accepted accounting principles (GAAP). It’s also called an “input error” because, though the number is correct, it’s recorded in the wrong account.
For example, personal expenses are accidentally recorded as business expenses in the books.
Errors of Commission
An error of commission occurs when an amount is entered right and in the correct account but the value is wrong–i.e. it’s subtracted instead of added or vice versa.
For example, a payment is applied to the wrong invoice. The amount owing by the client will still be correct in the trial balance, obscuring the mistake.

Errors of Reversal
When an entry is debited instead of being credited, or vice versa, this is an error of reversal.
For example, a $500 invoice sent to a client is posted in accounts payable instead of accounts receivable.