There is no single answer. Being a sole trader is the simplest way to start; a company (Spanish SL, Estonian OÜ or US LLC) separates your assets from the business and may offer tax advantages, but adds costs and duties. The choice depends on your volume, how much profit you reinvest, and where you live and run the business.
*Reviewed on 1 October 2026. Informational guide, not tax advice.*
Indicative comparison
| Aspect | Sole trader | Spanish SL | Estonian OÜ | US LLC |
|---|---|---|---|---|
| Complexity | Low | Medium | Medium | Medium |
| Liability | Personal, unlimited | Limited to capital | Limited to capital | Limited |
| Profit taxation | Progressive income tax | Corporate tax | 0% retained, 22% distributed | Depends on structure and residence |
| Duties | VAT and income tax | Bookkeeping and annual accounts | Bookkeeping and annual reports | Annual US filings |
Rates change; check them before deciding.
When each usually fits
- Sole trader: you are starting, sell little, or are testing the business.
- SL: you invoice regularly and want limited liability at home.
- Estonian OÜ: you reinvest profit and sell in the EU; first analyse tax residence risk (guide to an Estonian company).
- LLC: you mainly sell on Amazon US or have an international structure (US LLC).
The most overlooked risk is assuming a foreign company automatically pays less: if you run it from Spain, it may be taxed there.
FAQ
Can I sell on Amazon without registering as self-employed? If it is regular and for profit, Spanish authorities treat it as an economic activity. Check your case with an adviser.
Other options besides sole trader? Yes, the companies in the table; also see how to report Amazon FBA income in Spain.
How Data Biz helps
We set up OÜ and LLC and handle their bookkeeping and VAT. Request a free consultation to compare with your own numbers, or read tax advice for Amazon sellers.
Sources and review
Estonian taxation: e-Residency. Spanish obligations: Spanish Tax Agency. Reviewed on 1 October 2026.