Some follow-up comments to your questions:
- Just keep in mind, that book and tax could have different lives, methods, etc. When this occurs, there is a book to tax difference recorded on the tax return to account for this; in the Schedule M-1.
- Since you are most likely not preparing your books in strict accordance with GAAP, it is possible that you may not have any difference between the two depreciation methods.
- Useful lives for tax, are determined using an old revenue procedure (Rev Proc 87-56). You can Google the revenue procedure. At that point you would look for the appropriate asset class and life.
*A reminder that posts in a forum such as this do not constitute tax advice.
Also keep in mind the date of replies, as tax law changes.
