If you are looking to bid for an upgrade on Virgin Atlantic through their "Your Bid" system, you can typically place your offer as soon as you have a confirmed booking, up until two days (48 hours) before your flight. Virgin usually sends out an email invitation to eligible passengers about seven days before departure, but you can also check your eligibility manually on their website under "My Booking." The best time to finalize your bid is often around the 72-hour mark, as the airline begins to assess the remaining cabin availability at that time. Bids are generally evaluated between seven days and 48 hours before the flight, and you will receive an email notification if your bid was successful. It is a "blind" auction, so you won't know what others are bidding. If your bid is accepted, your credit card will be charged immediately, and the upgrade becomes non-refundable. If you aren't successful, you keep your original seat and no money is taken. Remember that if there are multiple people on your reservation, you must bid for everyone in the party.