The filing requirement is triggered only if the value of the transaction and, in some cases, the size of the parties, exceed certain dollar thresholds, which are adjusted over time. For the purpose of determining the "size of the parties" one assesses the size of the party to the transaction, its ultimate parent entity, and all subsidiaries of that ultimate parent entity.
The general rule was a filing was required if three tests are met; (1) the transaction affects commerce; (2) either (a) one of the parties has sales each year or assets of US$100 million or more [as of 2008, raised to $126.3 million] and the other party has sales or assets of $10 million or more [2008:$12.6 million]; or (b) the transaction is valued at $200 million or more [2008:$252.3 million]; and (3) the value of the transaction is $50 million or more [2008:$63.1 million]. Some assets are not counted, generally assets that do not produce income. For example, if one of the parties involved in the transaction is a person, for the purposes of determining whether they reach the asset trigger, the value of their residence and the sports car that they drive are not counted, but the value of a second home that was rented out would be. There are certain exceptions on transaction reporting for usual and customary transactions, e.g. an airline purchasing planes, or certain real estate transactions such as for purchasing land used for buildings used by the acquiring party (an exception to the exception is that if the transaction is for a hotel-casino then the transaction is not exempt if the three conditions above are met). An example was given that a merger of two corporations each having a net asset value of $99 million would not require a filing. Presumably this would be raised to the current floor limits under the current rules, e.g. two corporations with assets of $125 million each could merge without triggering the reporting requirements.
The firm that is making the proposed acquisition is required to pay a substantial filing fee when making its filing; the amount of the fees is tied to the size of the transaction, as of 2008 the fee was $45,000 for transactions of $50 million to $100 million; $125,000 for transactions of $100 million to $500 million; and $280,000 for transactions over $500 million. Also, the filing fee is good for, during a period of up to one year after the original transaction, further transactions do not exceed the next threshhold, e.g. if a transaction was reported amounting to $78 million, the acquiring party could make additional purchases as long as they did not exceed $100 million within one year after the original filing. Once they reached $100 million, a new filing and new fee would be required, but no further fee would be required unless the total of purchases reached $500 million. There are also filing requirements based on the percentage of acquisition, at 25% of a company worth $1 billion, or 50% of any company if filing is required. However, once 50% or more of the target had been acquired or the amount of acquisitions reported exceeded $500 million, no further reports are required to be filed.
In transactions where either the FTC or the Antitrust Division believes there may be significant anticompetitive consequences, either agency may require more background information from the parties to the merger by means of the second request process.