This is something I’m pretty certain many small business and sole traders are completely unaware of, plus there are probably many who are aware but will take the risk (and the potential large fine if caught!).
Under the law, if you handle personal information about individuals, you have obligations to protect that information under the Data Protection Act.
The likelihood is that if you hold information pertaining to individuals or companies, you will need to be registered with the Information Commissioner’s Office (ICO) as mandated by the UK Data Protection Act 1998, which records the name of the data controller and the purpose(s) for the processing of the data processed by that controller within the meaning of The Act.
As always, registration carries a fee, the proceeds of which fund the UK Information Commissioner’s Office directly, although for many small businesses this is relatively modest (£35 at the time of writing).
For full information, please go to the ICO website at https://ico.org.uk/.