Example: a law firm advertises on its website that 99% of H-1B Visa Application they fill are accepted. Is the law firm legally bounded to state the true number, or can it state any number they feel like it?
I am mostly interested in the United States.
If this claim were made in Australia it would most certainly have to be materially correct. Australian Consumer Law prohibits "false or misleading statements in trade or commerce"; action may be taken by individuals or the federal government through the Australian Competition and Consumer Commission (ACCC) and/or the Fair Trading (or similar) departments of each of the states or territories. The Australian Consumer Law is "harmonised" legislation meaning that it is the same in each Australian jurisdiction except for necessary administrative differences.
It is worth noting that this is an objective test:
The information provided by the defendant is tested by reference to the reaction of hypothetical ordinary, reasonable readers as to what was the dominant message conveyed to them. It is enough for relief to be granted that the statement or advertisement has a tendency to lead such persons into error. It is not necessary for the court to find that it is more likely than not that the readers were led into error, and it is enough that there is a real and not remote possibility of the reader being misled or deceived.
http://barristers.com.au/wp-content/uploads/2014/11/Misleading-or-Deceptive-Conduct-Cases-Western-Australian-Developments-Paper.pdf (Note that this refers to Sections of the Trade Practices Act - these have now been subsumed into the Australian Consumer Law).
This means that it doesn't matter if there was an intention to deceive or mislead or even if the statement was objectively "true" or not.
