Planned changes to the Construction Skills Certification Scheme mean that from September 2017, Construction Related Occupation (CRO) cards will be phased out. Without registration on an accepted course, or an industry-recognised qualification for your trade, you will not be able to apply for a CSCS card, unless you apply for the CSCS Labourer Card, to access construction sites.
An IOSH Working Safely Certificate, along with a CITB Health & Safety Certificate, allows you to apply for a Labourer Card. Therefore, from September 2017, without a CSCS card, you won't get on site. The Labourer Card may be the only way you can get on site.