[1]​ The assignment of workers is a service contract between companies, making the workers of the assigning company available to the assigning company.

Spain

In accordance with the Workers' Statute "Workers' Statute (Spain)") the hiring of workers to temporarily assign them to another company may only be carried out through duly authorized temporary employment companies.

In any case, it is understood that the illegal transfer of workers contemplated in this article is incurred when any of the following circumstances occur: that the object of the service contracts between the companies is limited to a mere provision of the workers of the transferring company to the transferring company, or that the transferring company lacks an activity or its own stable organization, or does not have the necessary means for the development of its activity, or does not exercise the functions inherent to its status as entrepreneur.

Employers, assignor and assignee, who violate what is stated in the previous sections will be jointly and severally liable for the obligations contracted with the workers and with Social Security, without prejudice to other responsibilities, including criminal ones, that may arise from said acts.

Workers subjected to prohibited trafficking will have the right to acquire permanent status, at their choice, in the transferring or assigning company.