Bids are accepted on a first-come-first-serve basis. If multiple users click “Bid Now” button simultaneously, the first request to reach the server will be recorded as the ‘valid bid’. Other users will get a message stating that their bids were not validated. The auction closes at the specified closing time or X minutes after the last bid is placed, whichever is later. This process ensures that everyone always have a chance to outbid the last bidder.