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| Khoh Tio Ching | 4874 | Tunnelling Engineering | 2022-10-20 | Engineers 717 Pte. Ltd. |
| Khoo Kok Sing | 3220 | Geotechnical Engineering | 2007-01-26 | KTP Consultants Pte Ltd |
| Khoo Kok Sing | 3220 | Tunnelling Engineering | 2022-03-24 | KTP Consultants Pte Ltd |
| Khoo Wen Jia | 5454 | Lift and Escalator Engineering | 2022-03-24 | TUV SUD A-Reliance |
| Koay Hean Lye Kelvin | 1563 | Access Platform Engineering | 2017-09-19 | Koays Consulting Pte Ltd |
| Koay Hean Lye Kelvin | 1563 | Lift and Escalator Engineering | 2017-09-19 | Koays Consulting Pte Ltd |
| Koh Yan Leng | 4833 | Crane Engineering | 2016-10-18 | KYL ENGRG (S) PTE. LTD. |
| Koh Yan Leng | 4833 | Lift and Escalator Engineering | 2020-08-20 | KYL Engrg (S) Pte. Ltd. |
| Koh Yan Leng | 4833 | Access Platform Engineering | 2021-06-24 | KYL Engrg (S) Pte. Ltd. |
| Koh Yong Hong | 4537 | Protective Security Engineering | 2018-09-20 | Defence Science and Technology Agency |
| Koh Zhi Wei | 4649 | Geotechnical Engineering | 2022-01-27 | JIB Specialist Consultants Pte. Ltd. |
| Kong Tze Foong | 4411 | Geotechnical Engineering | 2019-12-05 | Building and Construction Authority |
| Kwan Choon Shien Stephen | 3896 | Geotechnical Engineering | 2007-07-19 | KTP Consultants Pte Ltd |
| Lai Woei Tong | 3566 | Geotechnical Engineering | 2007-03-15 | T.Y.Lin International Pte. Ltd. |
| Lai Yun Tai | 3710 | Lift and Escalator Engineering | 2018-12-14 | P&T Engineer Services |
| Lau Kok Choy Colin | 4392 | Crane Engineering | 2017-10-23 | Integ Engineering Pte. Ltd. |
| Lau Kok Choy Colin | 4392 | Pressure Vessel Engineering | 2017-10-23 | Integ Engineering Pte. Ltd. |
| Lau Kok Choy Colin | 4392 | Lift and Escalator Engineering | 2017-10-23 | Integ Engineering Pte. Ltd. |
| Lau Kok Choy Colin | 4392 | Access Platform Engineering | 2017-10-23 | Integ Engineering Pte. Ltd. |
| Lau Wei Hing | 3670 | Geotechnical Engineering | 2009-05-21 | Emerald Asia Consulting Pte. Ltd. |
| Lee Hiang Meng | 4067 | Geotechnical Engineering | 2011-03-17 | PAL Consultancy Pte. Ltd. |
| Lee Hong Keow | 2307 | Geotechnical Engineering | 2007-05-17 | Fong Consult Pte Ltd |
| Lee Kah Chan | 3061 | Tunnelling Engineering | 2025-06-19 | Geoconsult Asia Singapore Pte Ltd |
| Lee Kah Chan | 3061 | Geotechnical Engineering | 2007-07-19 | Geoconsult Asia Singapore Pte Ltd |
| Lee Kian Chew Thomas | 2981 | Lift and Escalator Engineering | 2018-02-13 | TL Consultancy Services Pte Ltd |
| Lee See Loi | 2455 | Lift and Escalator Engineering | 2017-10-23 | Lee S L Engineering Enterprise |
| Lee See Loi | 2455 | Crane Engineering | 2017-03-23 | Lee S L Engineering Enterprise |
| Lee Si Min | 5328 | Lift and Escalator Engineering | 2024-06-27 | Building and Construction Authority |
| Lee Siew Kee | 3195 | Lift and Escalator Engineering | 2018-09-20 | SGSPE Pte. Ltd. |