&gt; GAAP rules state that anything paid above &quot;book value&quot; for the company must be called &quot;good will&quot; and be depreciated.<p>Goodwill is not subject to amortization since 2001 (depreciation is the term for tangible assets, amortization for intangible assets). It has to be tested for impairment, though. For example, HP bought Autonomy for $11.1bn in 2011 and took an impairment charge of $8.8bn in 2012 (the goodwill and a good chunk of the book value as well).