Lounge access usually comes with status or a business class ticket. Star Alliance also sells it, on the conditions below.
Who can buy it
You must be flying a Star Alliance member airline that day: “Yes, you have to fly on a Star Alliance Member Carrier flight.”
You do not need frequent flyer status or a business class ticket. Travellers often get this wrong, and it is what makes a paid lounge a real option on an economy ticket:
No. If you have purchased a lounge access through our reservation website, there is no need to have a frequent flier status, or business class of travel to access the lounge.
There is an age limit: “You must be at least 18 years of age to reserve lounge access. You may be asked for valid identification document at lounge entrance.”
Star Alliance publishes no price. Each lounge is quoted when you book, with no range to plan against. If you want the cost before you commit, Jetpac sells lounge entry with the price shown up front. Neither company publishes which lounges the Jetpac pass opens, so check the one at your gate rather than assume.
What to show at the door
Both documents, together: “Please present your lounge reservation alongside your valid boarding pass with same day of travel to be admitted into the lounge.” A boarding pass for another day will not do.
Group size and the three-hour cap
One booking covers a group: “You may create a reservation for a travel party of up to 9 persons, including yourself.”
The stay is limited: “The lounge reservation provide for a maximum three hour stay in the Lounge unless otherwise indicated on the Access Document or by the Lounge.” A long layover can outlast it.
If yours will, look outside the alliance. Plaza Premium runs lounges in the same terminals at most large Asian hubs and sells entry by the visit, with the price on each lounge’s own page. It is not a Star Alliance lounge, it will not honour a Star Alliance reservation, and you pay for it separately. It is the fix for three hours used up with the flight still four hours away.
Changing or cancelling
You can edit your name, email, flight number and comments. The date and time are fixed: “Please note that you cannot modify reservation date and time. To change this information, you must cancel and re-do your reservation.”
A refund depends on your flight being cancelled or delayed: “All Lounge Access reservations are fully refunded if cancelled less more than the 24 hours prior to the estimated time of entrance due to your flight being cancelled or delayed for more than 4 hours.” The muddled middle of that sentence is Star Alliance’s own wording. Read it twice before you rely on it.
A prepaid pass covers a bad flight from the other side. Instead of refunding a booking you can no longer use, the delay product that comes with one opens a lounge when your flight is cancelled or badly late. On a route where delays are the usual problem, that is sometimes the better deal.
What the lounge pages leave out
Star Alliance does not say what is inside any lounge. Showers, hot food and quiet space vary a great deal between an alliance flagship and a small contract lounge, and the access rules are the same for both. Look up the lounge before you pay for three hours in it. Plaza Premium makes that easier, because it prices entry against a named lounge’s own page, while a Star Alliance reservation does not tell you which room you are buying.
Plaza Premium sells entry by the visit, priced on the lounge's own page (affiliate link)
Jetpac sells lounge entry with a price you can see before you fly (affiliate link)