Self-employed by mutual agreement?

The important thing in these cases is to analyze how the services will actually be provided, and not how the parties (i. e., the company and the worker) decide to call them or how the contract is formalized. If the person will work within the company, under its organization, following its instructions and carrying out the activity as another worker:

• There will be an employment relationship, even if both parties agree to sign a formal commercial contract and use self-employed invoices.
• The agreement between employer and worker does not eliminate the risks. The status of self-employed does not depend on the will of the parties, but on how the activity is actually carried out.

For example, if the person goes to the workplace daily, uses the company's resources, works with fixed hours, receives instructions about orders, or only enjoys vacations and permits when the company accepts them (among other signs), it will be difficult to consider them a true independent professional.

Moreover, the fact that the worker themselves proposes to register as self-employed does not prevent them from later claiming the existence of an employment relationship (the situation may be peaceful at first and deteriorate over time). At the time of termination, the same person can demand that the company pay them the compensation corresponding to an employee (or the recognition of wage differences, contributions, and any other rights derived from a regular employment relationship).

Likewise, the Labor and Social Security Inspection can act, even if no complaint has been filed. That is, a random inspection visit or a workplace accident can uncover the situation, resulting in significant debt for Social Security contributions, surcharges, fines, and interest.