Conduct recognizing the existence of a transaction and intended to permit the transaction to be carried into effect; a tacit agreement; consent inferred from silence.
For example, a new beer company is concerned that the proposed label for its beer might infringe on the trademark of its competitor. It submits the label to its competitor's general counsel, who does not object to its use. The new company files an application in the patent and trademark office to register the label as its trademark and starts to use the label on the market. The competitor does not file any objection in the Patent Office. Several years later, the competitor sues the new company for infringing on its trademark and demands an accounting of the new company's profits for the years it has been using the label. A court will refuse the accounting, since by its acquiescence the competitor tacitly approved the use of the label. The competitor, however, might be entitled to an injunction barring the new company from further use of its trademark if it is so similar to the competitor's label as to amount to an infringement.
Similarly, the internal revenue service (IRS) may acquiesce or refuse to acquiesce to an adverse ruling by the u.s. tax court or another lower federal court. The IRS is not bound to change its policies due to an adverse ruling by a federal court with the exception of the U.S. Supreme Court. The chief counsel of the IRS may determine that the commissioner of the IRS should acquiesce to an adverse decision, however, thus adopting the ruling as the policy of the IRS. The decision whether to acquiesce to an adverse ruling is published by the Internal Revenue Service as an Action on Decision.
Acquiescence is not the same as laches, a failure to do what the law requires to protect one's rights, under circumstances misleading or prejudicing the person being sued. Acquiescence relates to inaction during the performance of an act. In the example given above, the failure of the competitor's general counsel to object to the use of the label and to the registration of the label as a trademark in the Patent and Trademark Office is acquiescence. Failure to sue the company until after several years had elapsed from the first time the label had been used is laches.