| Ong Chong Ping | 1583 | Lift and Escalator Engineering | 2017-03-23 | Eletrain Pte. Ltd. |
| Ong Chong Yao | 4647 | Crane Engineering | 2017-03-23 | - |
| Ong Chong Yao | 4647 | Access Platform Engineering | 2017-05-22 | - |
| Ong Chong Yao | 4647 | Lift and Escalator Engineering | 2017-05-22 | - |
| Ong Chung Wei | 4826 | Lift and Escalator Engineering | 2018-02-13 | - |
| Ong Chung Wei | 4826 | Access Platform Engineering | 2017-06-15 | - |
| Ong Chung Wei | 4826 | Crane Engineering | 2020-08-20 | - |
| Ooi Poh Hai | 4607 | Geotechnical Engineering | 2014-10-21 | A-Terra Consultants Pte. Ltd. |
| Oskar Sigl | 3720 | Tunnelling Engineering | 2022-01-27 | Geoconsult Asia Singapore Pte Ltd |
| Oskar Sigl | 3720 | Geotechnical Engineering | 2007-03-15 | Geoconsult Asia Singapore Pte Ltd |
| Pang Piow Chi | 1319 | Pressure Vessel Engineering | 2017-08-22 | Greenridge Trading |
| Pang Suh Ju | 4221 | Pressure Vessel Engineering | 2017-04-20 | Divine Engineering Services |
| Pang Suh Ju | 4221 | Crane Engineering | 2017-04-20 | Divine Engineering Services |
| Pang Suh Ju | 4221 | Lift and Escalator Engineering | 2017-04-20 | Divine Engineering Services |
| Pang Suh Ju | 4221 | Access Platform Engineering | 2017-04-20 | Divine Engineering Services |
| Peerapong Suthiwarapirak | 4397 | Geotechnical Engineering | 2016-02-16 | Aurecon Singapore (Pte.) Ltd. |
| Pham Thanh Hai | 4661 | Geotechnical Engineering | 2018-07-19 | Strader Consult Pte. Ltd. |
| Phoon Hung Leong | 4710 | Geotechnical Engineering | 2023-04-27 | WSP Consultancy Pte. Ltd. |
| Phua Hong Aik | 3500 | Lift and Escalator Engineering | 2017-03-23 | PHA Consultancy |
| Png Eng Chiok | 2706 | Lift and Escalator Engineering | 2017-04-20 | - |
| Poh Chee Kuan | 1429 | Geotechnical Engineering | 2007-07-19 | Longrove & Associates Pte. Ltd. |
| Poh Kong Beng | 1665 | Geotechnical Engineering | 2007-04-19 | Marsfield Consultants |
| Poh Teoh Yaw | 3898 | Geotechnical Engineering | 2007-04-19 | Building and Construction Authority |
| Pong Mew Lan Marina | 3253 | Geotechnical Engineering | 2019-03-21 | Sembcorp Architects & Engineers Pte. Ltd. |
| Quek May Lian Jeslin | 4030 | Protective Security Engineering | 2019-09-19 | Fyfe Asia Pte Ltd |
| Rengasamy Selvaraju | 3686 | Geotechnical Engineering | 2025-03-27 | AECOM Singapore Pte. Ltd. |
| Roger Martin Nicholas | 1012 | Lift and Escalator Engineering | 2018-01-08 | Conpro Services Pte Ltd |
| Roger Martin Nicholas | 1012 | Access Platform Engineering | 2018-01-08 | Conpro Services Pte Ltd |
| Roger Martin Nicholas | 1012 | Crane Engineering | 2018-01-08 | Conpro Services Pte Ltd |
| S Chandrasegaran s/o Sundararaju | 4346 | Geotechnical Engineering | 2012-03-22 | Jacobs International Consultants Pte. Ltd. |