For four years, Chin Ming Lik used fake qualifications to get civil engineering jobs at 38 companies, some of which paid him a salary of up to $9,000 monthly.
The 49-year-old worked at each company for short periods of time between 2013 and 2017, and moved on quickly to avoid suspicion.
Among the documents he forged were a National University of Singapore (NUS) degree scroll, certificates from the Ministry of Manpower and Singapore Polytechnic, and a GCE A-level certificate.
Chin, whose highest academic qualification is the Primary School Leaving Examination, was sentenced yesterday to two years and 11 months' jail, and fined $1,600 for his offences.
Deputy Public Prosecutor Tan Pei Wei told the court the ruse came to light on Dec 2, 2016, when an assistant manager at NUS' Registrar Office received an NUS degree scroll with Chin's name for verification.
As the scroll did not match any of the records in the university's database, it was suspected to have been forged for job application purposes, and the assistant manager lodged a police report.
Chin was placed on a police stop list to assist with investigations. He was later arrested at Woodlands Checkpoint on April 23, 2017.
During investigations, he admitted to forging multiple certificates for courses he had never attended .
These included a scroll for an NUS First Class degree in Civil Engineering and a Building Construction Supervisors Safety Course Certificate supposedly from the Ministry of Manpower, both of which he had forged in or before January 2014.
DPP Tan said: "He had heard that project managers in civil engineering drew good salaries and decided to forge the relevant certifications in order to obtain jobs in the field."
In his resume, Chin falsely said he had 16 years of experience and had previously worked for construction companies in Singapore.
About two weeks before his offences were discovered, he had applied for a job as a project manager with CHL Construction, using the same forged documents.
He was offered the job, but turned it down as he considered the monthly salary of $7,500 too low.
In a search of Chin's apartment after his arrest, the authorities found a forged GCE A-level certificate and a Singapore Polytechnic certificate.
Chin had forged the documents by photocopying other people's certificates which he had found in previous jobs.
He laid slips of paper with his details over the relevant fields and then photocopied them again.
He made a statutory declaration on Sept 9, 2015, to excuse his inability to provide original copies of the forged certificates submitted during job applications.
It stated that he had misplaced 10 original certificates when he moved house, a statement he knew to be false, said DPP Tan.
Chin's other offences included not possessing a valid driving licence at the time of his arrest in Woodlands. He held only a provisional licence as he had been disqualified from driving since 1992.
However, he admitted to driving four cars without a valid licence over the past 10 years.
Chin also committed shop theft at an NTUC FairPrice outlet in Bedok North on Sept 19, 2017, while out on court bail for the forgery offences.
Defence lawyer James Ow Yong said in mitigation that Chin, who was "deeply remorseful", is the sole breadwinner of his family.
District Judge Shaiffudin Saruwan said Chin had received corrective training for past offences but there had been "no rehabilitative effect", hence the decision to issue a sentence that serves as a deterrence.