When must amendments be sent to everyone to whom invitations have been furnished?

Amendments must be sent to everyone who has received invitations before the time for bid opening because ensuring all potential bidders have the same information is crucial for maintaining a fair and competitive bidding process. This requirement helps to ensure transparency and equal opportunity among all participants, which is a fundamental principle of procurement practices. By distributing amendments prior to the bid opening, all bidders can adjust their proposals accordingly based on the changes, thus leading to a more accurate and competitive bidding environment. This timing is essential to uphold the integrity of the bidding process, allowing everyone to have an equal understanding of the requirements and expectations.