By law, the employer has the obligation to report the details of the workers he employs in his household. Failing to report the worker's information is regarded as if the employer did not fulfill his obligation at all, and may be detrimental to the worker's rights at the National Insurance Institute, even if insurance contributions were paid on his behalf.
Besides, in the occurrence of an event entitling the worker to a benefit, assuming that at the time of that event the employer did not properly register his worker as required by law or failed to pay insurance contributions on time, the National Insurance Institute has the ability to demand payment from the employer of the same amount of money paid as benefits to the worker in relation to that same event, in addition to the settlement of his arrears in insurance contributions.