By train
The Thai side of Padang Besar has a small railway station which should not be confused with the Padang Besar station on the Malaysian side where all Thai and Malaysian immigration formalities are carried out. The station is on the right side of the road leaving town towards Hat Yai. The following are departures from the Thai Padang Besar station, hence the times are all Thai time.
Both Keretapi Tanah Melayu's Senandung Langkawi express between Kuala Lumpur and Hat Yai and the State Railways of Thailand's International Express between Bangkok and Butterworth in Penang stop for a short while before proceeding to or after coming from Malaysia. The Senandung Langkawi departs for Hat Yai at 08:45 and for Kuala Lumpur at 15:45. The International Express leaves Padang Besar for Bangkok at 16:30 and for Butterworth at 07:20.
Note that Malaysia is one hour ahead of Thailand. When it is noon in Thailand, it is 13:00 in Malaysia.
By road
Padang Besar is located about 50km south of Hat Yai. Coming from Hat Yai, you will have to turn right west at Sadao town. To get to the Malaysian town of Padang Besar, leave town on the road to Hat Yai and the Thai immigration checkpoint is about 1km away on the right.
The border crossing is open 05:00-23:00 Thai time 06:00-midnight Malaysian time.
Bus to/from Hat Yai: Regular local buses link Padang Besar and Hat Yai via Sadao. Journey time is about one hour. Buses leave from the main town square. The bus can also be caught on the main road right outside the Thai immigration complex. Wait on the opposite side of the road for Hat Yai-bound buses. Buses stop running around 6pm, so it is advisable to check.
Bus to/from Malaysia: There are no direct buses. From Hat Yai, get off the bus at the Thai immigration complex and walk or take a motorcycle taxi 20 baht or RM2 should be enough. If you choose to walk, remember that the two immigration checkpoints are several hundred metres apart. There is a duty free shopping complex in between the checkpoints on Malaysia territory.