Legally, if you don’t have any employees you do not have to have insurance for your business, however this would leave you fully responsible for all the things related to your business such as loss or damage. This means that if anything happened to you at work or to your business premises, equipment or stock etc you would have to pay for it all yourself. An example of this would be if your property was damaged due to fire or your business equipment was stolen.
With the right business insurance you can insure against risks to your business so you will be covered if the worst happens. If you do not have public liability insurance, which covers you for injury or property damage to a third party, you would be liable for claims made against you if your product or service damaged a member of the public.
Legally you are required to have employer’s liability insurance if you have anyone working for you in any capacity. You can find out the description of an employee here if you are unsure. Employer’s liability is never sold alone; it will always come as a package with public liability.