ONCO SES ltd is a family run business that was established in 2020 by company director Callum O'Neill, a qualified electrician with 12 years experience in the industry. There are more than 50 years experience across ONCO's workforce in the electrical industry, ranging from household domestic electrics up to directorship in one of the worlds leading Exhibition event companies. 

Callum is City and Guilds qualified which a multitude of experience in Electrical Operations Management, Electrical Foreman, and Labour Management inclusive of electrical installation. Callum was previously an Electrical Operations Manager for Freeman EMEA working all over the world.

As a company, we are fully dedicated to client satisfaction. In all that we do, we strive to work meticulously and with integrity in order to provide high-quality results in all our projects.


Many companies will try and undercut each other in order to secure a job, however here at ONCO SES, we aim to be price transparent. This means we don't aim to beat your quotes, but be rest assured that our prices are honest, cost effective and allow us to use the best quality materials available on the market. This also means there are no hidden costs. Some companies will quote less in order to secure a job, but then charge additional when they hit a 'problem'.  

We believe that communication is key, and our customer service is always something we are complimented on. No job is too big or too small, and we're always happy to provide advice.

Electrical Construction Plans
Domestic Installer

Our Electricians

Are friendly and reliable skilled contractors, who have years of electrical experience and knowledge. You can always expect the best quality of work.