We and all the other Phuket rent-a-car companies are currently located just across the road, in old and very congested office & parking space.
The other important piece of information I must share with you is, there no longer is any local petrol station at the airport, or the close proximity?
I have no idea why, but the last remaining gas station at the airport has closed.
This now means if you are returning a car and want to top up the tank, you must do this at the only Petrol Station before the airport on the main road from Phuket Town (south of the island) the 402, the is only a few hundred meters/yards from the main junction where you would leave the 402 turning left at the traffic lights using the exit lane on to the 4026
The precise location of this SUSCO garage is shown on the map to the left of these instructions. It is about 5 miles from the airport.Make sure you check to see if it is diesel or petrol you need.
Always ask for a receipt, it may be useful if ever you are challenged as to whether you filled up the tank or not. The thai word for receipt is "bizet" (pronounced bi set)
Okay so now you should be heading toward the airport on the 4026, this is a fast bit of road, with some dual carriageway and is currently being widen and renewed.
Eventually after about 5 minutes of travelling, having turned left off the 402, you reach the end of the road at newly constructed traffic lights where you turn right. On route you may see a garage hidden on the right hand side, don't be fooled this is a LPG station only.
Drive another few minutes and the main entrance to the airport is on the left hand side next to a very large portrait of the king.
If you can take a few photos of the car with your phone, it is always advisable. Check over any paperwork with the staff and be sure that any damage/marks are agreed, if appropriate. Get back any receipts, especially the "deposit credit card receipt", which is normally held until the car is returned. Allow yourself at least 20 minutes for the return of the car, the inspection and paperwork formalities. Bon Voyage !