The Government of Thailand has approved a THB36 billion budget for works on the third phase of the Don Mueang Airport project. Majority of this will be financed by internal revenues of the Airports of Thailand (AoT), with remaining funds obtained from external sources.

Work under phase 3 will be carried out in six phases with the first phase including the construction of a new passenger terminal and a concourse. The remaining phases will include the construction of a flight operation area, renovating passenger terminal building 1 and the aircraft parking bays and expanding the northern concourse. A seven-storey car park will also be renovated.

The airport currently has two passenger terminals, with a combined capacity of 30 million passengers annually. Once the expansion project is completed, the airport will be able to handle 40 million passengers annually. Additionally, the capacity-boosting project will also alleviate road and air traffic at the Don Mueang Airport.