Just a reminder that if you have been depreciating an asset for the wrong class life, you have two options:
If you have been doing it wrong for only 2 years, then you can amend the back year returns to correct and then go forward correctly.
If you have been doing it incorrectly for more than 2 years, in order to correct it, you will have to use IRS Form 3115 to Change the Accounting Method and adjust depreciation taken in year discovered and then future years can be handled correctly.
Please see information on Form 3115:
IRS Form 3115, Change in Accounting Method
