The phrase "acted in breach" is correct and usable in written English.
It is typically used in legal contexts to indicate that someone has violated a law, regulation, or agreement.
Example: "The company acted in breach of the contract by failing to deliver the goods on time."
Alternatives: "violated the terms" or "breached the agreement".
She said he had acted in breach of the "requirements of transparency, certainty and clarity" and "irrationally".
West Ham said: "Diafra Sakho and West Ham United vigorously deny that they have acted in breach of Fifa regulations.
The health secretary had "acted in breach" of his "requirements of transparency, certainty and clarity" and behaved "irrationally", she told the court.
Imperial Tobacco said it was "disappointed" by the decision "and continues to reject any suggestion that it acted in breach of the Competition Act or in any way contrary to the interests of consumers".
The fact is that I have not and would never have acted in breach of the rules of the House of Commons, which I have scrupulously observed throughout the time I was an MP".
He added: "I conclude that [the group members] have acted in breach of the agreements by serving the notices, or, where they have not yet taken effect, will do so if they are not withdrawn".
We are, however, interested in any organisation which appears to act in breach of the equality enactments and thank you for drawing this matter to our attention".
"Any person who acts in breach of Section 19, which binds everybody, is potentially liable for breach of the order and can be referred to the high court for appropriate action," Leveson said.
"Professional footballers know that there are FA rules and if they take no trouble at all to find out what is in them, they cannot reasonably complain if they are charged and punished when they act in breach of the rules," concluded the commission's chairman, Nicholas Stewart QC, in his ruling on the Accrington Five.
Visitors here should know better than to ask a UK institution to act in breach of our culture of press freedom – and our civic institutions should know better than to kowtow to such a request, even if acting to prevent "embarrassment" for a guest.
Higgins was cleared of the most serious charges – of agreeing to accept a bribe and agreeing to engage in corrupt or fraudulent conduct – but found guilty of failing to report the illegal approach and intentionally giving the impression he was prepared to act in breach of betting rules.
