In the UK, you are self-employed if:
- run your business for yourself and take responsibility for its success or failure;
- have several customers at the same time;
- can decide how, where and when you do your work;
- can hire other people at your own expense to help you or to do the work for you;
- provide the main items of equipment to do your work;
- are responsible for finishing any unsatisfactory work in your own time;
- charge an agreed fixed price for your work;
- sell goods or services to make a profit (including through websites or apps).
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.
In the UK, you’ll need to register as self-employed to make sure you pay the correct Income Tax and National Insurance.
Always check to see what the legal requirements are in your country!
Also see: Business Structure.