Upgrade Awards with THAI and THAI Smile can be used with paid tickets in eligible booking classes, by member self or for an Award Nominee as follows:
Upgrades on THAI：
- A one sector upgrade on an international THAI operated flight (TG 3 digit) from Economy Class to Royal Silk Class or from Royal Silk Class to Royal First Class
Upgrades on THAI Smile：
- A one sector upgrade on an international THAI Smile operated flight (TG 4 digit only) from Economy Class to Smile Plus Class
Upgrades can be requested with THAI reservations worldwide at any time after a paid and eligible ticket has been issued, but not less than 24 hours prior to scheduled flight departure.
* A one sector upgrade using miles is subject a paid ticket with an eligible booking class and aircraft configuration to the next higher class of service as stipulated above. Some promotional fares may not be eligible for upgrading using miles.