Personally I would so any visitors/ contractors can see it too. Wherever I've worked its been displayed somewhere

This is atright from the horse's mouth, from the Horse and Safety Executive :-) publication 'Employer's Liability (Compulsory Insurance) Act 1969 - A Brief Guide for Employers: 'When you take out or renew a policy, your insurer will give you a certificate of employers’ liability insurance. This must state clearly the minimum level of cover provided and the companies covered by the policy. You must display a copy of the certificate of insurance where your employees can easily read it. Since 1 October 2008 you have been allowed to display your certificate electronically. Employers choosing this method need to ensure their employees know how and where to find the certificate and have reasonable access to it. Factors to consider include the availability of the chosen format and ensuring employees understand how to use it. For example, this arrangement may be suitable where all employees have access to a computer as part of their job.' So you do not need it on the wall and can 'display' it electronically, John

It certainly does Jodie, as the quote from HSE makes clear, John

Just a quick comment: EL Certs are irrelevant to visitors & contractors as the compulsory insurance cover applies to the employer only for his liability to his employees. The employer will choose whether to buy insurances that cover his liability to non-employees.