In-House Extension Numbers
| Be under | Telephone/Fax Number | |
| direct / center / #interior | Fax | |
| Expressway Authority of Thailand | 02-558-9800, 02-579-5380-9 | 02-561-2984 02-579-8737 |
| Office of the Governor | 02-579-5204, 02-558-9800 # 1240, 1224 | 02-579-5201 |
| General Affairs and Conference Division | 02-940-1262, 02-558-9800 # 2278, 2276 | 02-579-5201 |
| Public Relations Division | 02-579-9155, 02-558-9800 # 2298, 2299 | 02-579-9156 |
| Corporate Governance Division | 02-558-9800 # 2195, 2196, 2194 | 02-940-1210 |
| Business Development and Marketing Division | 02-558-9800 # 2255 | 02-940-1184 |
| Audit Office | 02-940-1245, 02-558-9800 # 2901 | 02-940-1245 |
| Internal Audit Division 1 | 02-940-1211, 02-558-9800 # 2906 | 02-940-1246 # 2727 |
| Internal Audit Division 2 | 02-579-0042, 02-558-9800 # 2926 | 02-940-1246 |
| General Administration Department | 02-579-8156, 02-558-9800 # 2005, 2003 | 02-940-1268 |
| Human Resource Management Division | 02-940-1212-13, 02-558-9800 # 2049 | 02-940-1213 |
| General Welfare and Employee Relations Division | 02-940-1212-13, 02-558-9800 # 2069-70 | 02-940-1230 |
| Human Resource Development Division | 02-940-1229 ,02-558-9800 # 2009 | 02-940-1230 |
| Procurement Division | 02-579-0043, 02-558-9800 # 2098 | 02-579-7735 |
| Organization Development Division | 02-579-0043, 02-558-9800 # 2012 | 02-940-1230 |
| Treasury and Accounting Department | 02-316-4476, 0-2746-9800-4 # 5070-1 | 02-940-1157 |
| Finance Division | 02-579-5164, 02-558-9800 # 2562 | 02-579-0037 |
| Accounting Division | 02-940-1155, 02-558-9800 # 2489 | 02-940-1155 |
| Budget Division | 02-558-9800 # 2466, 2458 | 02-940-1233 |
| Revenue Audit Division | 02-558-9800 # 2673 | 02-579-0044 |
| Finance and Funds Management Division | 02-558-9800 # 1585 | 02-579-0037 |
| Policy and Planning Department | 02-940-1219, 02-558-9800 # 2838, 2837 | 02-940 1219 |
| Planning and Project Analysis Division | 02-940-1224-6, 02-558-9800 # 2846 | 02-940-1225-6 |
| Evaluation Division | 02-558-9800 # 2867 | 02-579-9145 |
| Environmental Management Division | 02-558-9800 # 2862 | – |
| Information Technology Department | 02-579-5166, 02-558-9800 # 2348, 2347 | 02-561-2984 |
| Computer Application System Division | 02-940-1259, 02-558-9800 # 2352 | 02-561-2984 |
| 02-579-8737 | ||
| Computer Operations Division | 02-579-5206, 02-558-9800 # 2376 | 02-579-5206 |
| Expressway Construction Department | 02-249-6944-51 # 6136-6137 | 02-249-4923 |
| Expressway Engineering Division 1 | 02-240-0148, 02-249-9644-51 # 6137 | 02-249-4923 |
| Expressway Engineering Division 2 | 02-249-6375, 02-249-9644-51 # 6139 | 02-249-6375 |
| Design and Construction Division | 02-940-1217, 02-558-9800 # 2773 | 02-940-1217 |
| General Administration for Engineering Division | 02-558-9800 # 2806 | – |
| Maintenance Department | 02-319-9730-9 # 4135, 4130 | 02-319-7119 |
| Expressway Maintenance Division | 02-319-9730-9 # 4902 | 02-319-9730-9 # 4904 |
| Building and General Property Maintenance Division | 02-558-9800 # 4125-6 | 02-319-7119 |
| Equipment Maintenance Division | 02-319-9730-9 # 4161, 4164 | 02-319-9730-9 # 4162 |
| Electrical Mechanical Work and Vehicles Division | 02-319-9730-9 # 4703, 4836 | 02-319-9730-9 # 4831 |
| Land Acquisition Department | 02-247-2400, 02-248-6540, 02-641-5355-9 # 3403, 3404 | 02-247-1197 |
| Land Acquisition Division | 02-641-5355-9 # 3312, 3310 | 02-248-6483 |
| Property Development and Right of Way Maintenance Division 1 | 02-248-6890, 02-248-6574-6 # 3008, 3202 | 02-246-9390 |
| Property Development and Right of Way Maintenance Division 2 | 02-248-6492, 02-641-5355-9 # 3212 | 02-248-6492 |
| Legal Department | 02-319-7391, 02-558-9800 # 4301, 4318 | 02-319-7393 |
| Litigation Division | 02-319-7394, 02-558-9800 # 4319 | 02-319-7393 |
| Legal Affairs Division | 02-319-7392, 02-558-9800 # 4320 | 02-319-7393 |
| Traffic Control Department | 02-240-2292, 02-249-6944-51 # 6156, 6126 | 02-240-0709 |
| Traffic Management Division | 02-442-0883, 02-240-0426 | 02-442-0899 |
| 02-249-6944-51 # 6133 | 02-240-0709 | |
| Rescue Division | 02-319-9730-9 # 4118, 4151 | 02-319-9730-9 # 4153 |
| Traffic Communication and Special Rescue Operations Division | 02-558-9800 # 4150, 4118 | 02-558-9800#4153 |
| Toll Collection Department | 02-319-9724, 02-319-9726, 02-319-9730-9 # 4408 | 02-319-9725 |
| Toll Collection Division 1 | 02-319-9730-9 # 4421 | 02-319-9730-9#4429 |
| Toll Collection Division 2 | 02-319-9728, 02-319-9730-40 # 4414 | 02-319-7168 |
| Toll Collection Division 3 | 02-319-9730-9 # 4418 | 02-319-9725#4403 |
| Toll Collection Division 4 | 02-319-9730-9 # 4430 | – |
| E-Business Services Division | 02-319-9730-9 # 4254, 4253 | 02-319-9730-9 # 4255 |
| Operation Planning Division | 02-641-5355-9 | 02-247-1550#3510 |
| Risk Management and Internal Control Division | 02-558-9800 # 2812 | 02-558-9800#2546 |
| Research and Development Division | 02-558-9800 # 2946 | 02-558-9800#1729 |