As with any selling platform (e.g. Etsy, Facebook, Craft Fairs etc), if you’re selling goods or services with the intention of making a profit you should check if you qualify as a business. In the UK, a new tax allowance came into effect for income in the period 6 April 2017 to 5 April 2018 and you can turnover up to £1000 a year before needing to inform HMRC or fill in a Tax Return. If you turnover more, you will
need to register as a business/soul trader. You can be both employed and self-employed at the same time, for example if you work for an employer during the day and run your own business in the evenings.
If you decide to go self-employed, you should register with HMRC (if you’re in the UK). The general advice is that you should register with HMRC as soon as you start working for yourself, but you don’t have to rush to inform them. HMRC state that if you do start working as a sole trader you must register with them by 5 October of your business’ second tax year. So, if you started your business at any time during the 2019/20 tax year (from 6 April 2019 to 5 April 2020) you will need to register with HMRC by 5 October 2020.