Freelancers and self-employed persons who are paid exclusively by means of a Service Provision Bulletin (contracts under Annex 9, Article 39 Ν.4387/2016) or you are employed by an employer as employees and you provide services to up to 2 employers, you must indicate on the SRM issued to your employer that you are subject to this provision.
This ensures that contributions are paid on time and that those liable for payment are informed.