You can join multiple member airline frequent flyer programmes if you wish, but they are each managed separately, so you cannot transfer miles or points between them or combine them into one. By using a single frequent flyer programme whenever you fly, you will reach Star Alliance Silver or Gold status faster.

You cannot literally "merge" miles from different Star Alliance member airlines (like United, Lufthansa, and Singapore Airlines) into a single master account. Instead, the Star Alliance system is built on the principle of reciprocal earning and redemption. To maximize this in 2026, you should choose one "primary" frequent flyer program and provide that account number every time you fly with any of the 25 member airlines. For example, if you are a United MileagePlus member, you can earn United miles when flying on a Lufthansa flight. If you already have miles scattered across multiple accounts, your best option is to keep them there and use them to book "Partner Awards" through each respective airline's portal. Some airlines, like Air Canada or United, allow "Family Pooling" where you can combine miles with relatives within that same program, but they do not allow transfers from, say, ANA to Thai Airways. To avoid "orphaned" miles, always stick to one Star Alliance loyalty number for all your alliance-wide travel.