Yes, you can use your Turkish Airlines Miles & Smiles miles to upgrade a flight for someone else, even if you are not traveling with them. Turkish Airlines is relatively flexible with their "Business Upgrade" policy. To do this, the person you are upgrading must already have a confirmed economy class ticket in an eligible fare class (some deeply discounted or promotional fares may be excluded from mileage upgrades). You can process the upgrade by logging into your Miles & Smiles account on the official website or mobile app and entering the passenger's PNR (reservation code) and last name. Alternatively, you can call the Turkish Airlines call center to authorize the deduction of miles from your account for their seat. If you are a member of a "Family Membership" account, the process is even simpler as miles are pooled among family members. It is important to note that seat availability for mileage upgrades is limited and distinct from standard Business Class availability, so it is best to check for "Award Upgrade" space as early as possible. Once the upgrade is confirmed, the lucky recipient will enjoy the full Turkish Airlines Business Class experience, including lounge access and their award-winning onboard catering.