Sole proprietorship

A sole proprietorship is set up to allow an individual to own and operate a business by him/herself. A sole proprietor has total control, receives all profits from and is responsible for taxes and liabilities of the business.

If you are looking for a self-employment solution, you can start your activity as a sole proprietor. In Spain, Sole Proprietors are called autonomos.

As, almost everywhere else, a Sole Proprietorship is an unincorporated business owned by a single individual who bears unlimited personal liability for the business's debts. This form of business organizations does not require incorporation or commercial recording whatsoever. Filing with the Social Security Administration and the Tax authority is required. 

New regulations (Estatuto del Autonomo) have improved employment related contigencies for autonomos increasing their paid sick leaves and loosening requirements to collect unemployment. Locals do not cosideder that enough and would like to see autonomos treated as employees.

Indiviuals doing business as sole proprietors should be aware that their personal assets may be taken from you. If you form a company, then only the assets of the company are at stake.

Sole propietorships are an option when  starting out and the individual is not  ready to commit money for company formation and accounting. 

Besides the obvious risk of unlimited personal liability incorporating gives your business a better apparence  (keep in mind in Spain there are not such things as "DBA"s) and will make your cross-border transactions easier.