| Loh Yi-Shin | 3897 | Protective Security Engineering | 2019-02-21 | MOH Holdings Pte Ltd |
| Lok Tat Seng | 3164 | Protective Security Engineering | 2018-09-20 | PHM Technologies Pte. Ltd. |
| Loke Sim Wee Joshua | 4655 | Lift and Escalator Engineering | 2019-05-16 | JL Engineering and Consultancy Services Pte. Ltd. |
| Long Wenjiu | 4583 | Geotechnical Engineering | 2014-09-18 | CHECC(Singapore) Pte. Ltd. |
| Lu You | 5112 | Geotechnical Engineering | 2025-03-27 | Changi Airport Planners And Engineers Pte. Ltd. |
| Lum Chong Chuen | 1197 | Lift and Escalator Engineering | 1976-05-18 | LAC Engineers & Associates |
| Lum Shuet Meng | 0799 | Access Platform Engineering | 2017-03-23 | SM Engineering Services |
| Lum Shuet Meng | 0799 | Lift and Escalator Engineering | 2017-03-23 | SM Engineering Services |
| Lum Thim Kuai | 4214 | Lift and Escalator Engineering | 2017-06-15 | TUV SUD A-Reliance Pte. Ltd. |
| Lum Yun Kheun | 3732 | Crane Engineering | 2017-03-23 | YKLUM Pte. Ltd. |
| Lum Yun Kheun | 3732 | Access Platform Engineering | 2017-03-23 | YKLUM Pte. Ltd. |
| Lum Yun Kheun | 3732 | Lift and Escalator Engineering | 2017-03-23 | YKLUM Pte. Ltd. |
| Luo Xiangyue | 4400 | Geotechnical Engineering | 2015-06-18 | Arup Singapore Private Limited |
| Manivel S/O Rudrapathi | 4021 | Pressure Vessel Engineering | 2017-05-22 | R@dians Consultancy Services |
| Manivel S/O Rudrapathi | 4021 | Lift and Escalator Engineering | 2017-05-22 | R@dians Consultancy Services |
| Manivel S/O Rudrapathi | 4021 | Access Platform Engineering | 2017-05-22 | R@dians Consultancy Services |
| Manivel S/O Rudrapathi | 4021 | Crane Engineering | 2017-05-22 | R@dians Consultancy Services |
| Marcus Tan | 2593 | Lift and Escalator Engineering | 2021-07-21 | Eletrain Pte. Ltd. |
| Michael John McGowan | 4489 | Geotechnical Engineering | 2014-04-17 | Arup Singapore Private Limited |
| Michael John McGowan | 4489 | Tunnelling Engineering | 2021-07-21 | Arup Singapore Private Limited |
| Michael Sien Hay Wah | 4569 | Protective Security Engineering | 2018-09-20 | WSP Consultancy Pte Ltd |
| Mohamad Nasser B Mustapha | 2033 | Pressure Vessel Engineering | 2018-09-20 | Nasser & Associates |
| Mohamad Nasser B Mustapha | 2033 | Crane Engineering | 2019-02-21 | Nasser & Associates |
| Mohamad Nasser B Mustapha | 2033 | Access Platform Engineering | 2018-07-19 | Nasser & Associates |
| Mohd Ismadi Bin Mohamad | 3752 | Lift and Escalator Engineering | 2017-11-18 | Emaan Inspection Pte Ltd |
| Mohd Ismadi Bin Mohamad | 3752 | Pressure Vessel Engineering | 2017-11-18 | Emaan Inspection Pte Ltd |
| Mohd Ismadi Bin Mohamad | 3752 | Crane Engineering | 2017-11-18 | Emaan Inspection Pte Ltd |
| Mohd Ismadi Bin Mohamad | 3752 | Access Platform Engineering | 2017-11-18 | Emaan Inspection Pte Ltd |
| Mohd Kahliab Bin Zainal Abidin | 3330 | Pressure Vessel Engineering | 2017-09-19 | Emaan Inspection Pte Ltd |
| Mohd Kahliab Bin Zainal Abidin | 3330 | Crane Engineering | 2017-09-19 | Emaan Inspection Pte Ltd |