The Information Commissioner’s Office (ICO) is the UK regulator for data protection and information rights. Data protection laws are likely to apply to all illustrators as you’ll be using people’s data (emails, addresses for eg) as part of your regular business.
In August 2021 the ICO will be writing to organisations to remind them that they may have a legal responsibility to register with the ICO and pay the data protection fee. For most companies this is £35 or £55 per year when they pay by direct debit.
If you receive a letter, you should check if you need to pay and, if you believe you are exempt, you should let the ICO know by 25 September 2021. If you are not exempt, you will need to register through their website and pay the fee.
The ICO has a huge amount of resources, explainers, and step by step guides on their website. A good place to start is their web hub designed for small and medium enterprises which has lots of tips and simple guides that you will find useful.
This page explains what data protection is, what you need to do as well as answering any questions. It’s a good place to start if you are not familiar with it.