Under new procedures introduced by the Garda Carriage Office, each applicant for a Public Service Vehicle (PSV) licence must declare all previous convictions.
The move was prompted by the discovery last year that the man at the centre of the X case had received such a licence without the knowledge of gardai.
The first step in applying for a licence is getting a form from the motor tax office, which, when filled out, should be handed in to the applicant's local Garda station.
As well as checking for previous convictions, local gardai are meant to investigate whether the applicant recently had moved home or was known to other Garda stations.
The main reasons for a licence not being issued at this stage would be if the person had been convicted of serious driving offences or had been involved in organised crime. Being convicted of a sex offence does not automatically bar someone from holding a licence.
Once the background checks are completed, the applicant must pass a written test at the Carriage Office before being issued with a PSV licence. Some 2,500 applications were received by the office last year. A further 14,000 licences were renewed.