Now that you’ve chosen an accounting policy, you’re expected to apply it consistently. Consistently in this sense means from period to period the same way. 

That’s easy, right? Now, a situation may arise when you might need to decide upon a different approach at some point. Consistency is still a valid approach unless an accounting standard or interpretation requires or permits different accounting policies to be applied.

Of course, if it’s “required”, it’s required and there’s no other approach to take. However, if it’s “permitted” to use another approach, it’s up to the management to decide the way to account for this specific transaction or event. Note with this that whatever you choose, it still needs to meet the users’ needs above all and still be reflecting the substance of the transaction. There’s no way around it. Hence it’s not always useful to change an accounting policy.

Should this situation arise, note that the need to apply the policy consistently still applies. Once you’ve chosen a method that meets your needs and requirements set out to one, you must stick to it. It’s not allowed to change policies every year or even mid year all too often as you see fit because it looses the comparability above all. Changing policies to meet your goals when it comes to your company’s performance is especially biased if you think about it. The reason for sticking to one method means the financial statements do actually give a true and fair view of your financials.