An accounting principle is a general guideline to follow when recording and reporting financial transactions. There is a change in accounting principle when:
There are two or more accounting principles that apply to a particular situation, and you shift to the other principle; or
When the accounting principle that formerly applied to the situation is no longer generally accepted; or
The method of applying the principle is changed.
You should only change an accounting principle when doing so is required by the accounting framework being used (either GAAP or IFRS), or you can justify that it is preferable to use the new principle.
A direct effect of a change in accounting principle is a recognized change in an asset or liability that is required in order to effect the change in principle. For example, if you change from the FIFO to the specific identification method of inventory valuation, the resulting change in the recorded inventory cost is a direct effect of a change in accounting principle.
An indirect effect of a change in accounting principle is a change in an entity's current or future cash flows from a change in accounting principles that is being applied retrospectively. Retrospective application means that you are applying the change in principle to the financial results of previous periods, as if the new principle had always been in use.
You are required to retrospectively apply a change in accounting principle to all prior periods, unless it is impracticable to do so. To complete a retrospective application, the following steps are required:
Include the cumulative effect of the change on periods prior to those presented in the carrying amounts of assets and liabilities as of the beginning of the first period in which you are presenting financial statements; and
Enter an offsetting amount in the beginning retained earnings balance of the first period in which you are presenting financial statements; and
Adjust all presented financial statements to reflect the change to the new accounting principle.
These retrospective changes are only for the direct effects of the change in principle, including related income tax effects. You do not have to retrospectively adjust financial results for indirect effects.
It is only impracticable to retrospectively apply the effects of a change in principle under one of the following circumstances:
You make all reasonable efforts to do so, but cannot complete the retrospective application
Doing so requires knowledge of management's intent in a prior period, which you cannot substantiate
Doing so requires significant estimates, and it is impossible to create those estimates based on information available when the financial statements were originally issued