You may be thinking about EU law. I don't know whether this is universal to the EU, but in Germany it works the way you describe: even if you get paid to do it

You may be thinking about EU law. I don't know whether this is universal to the EU, but in Germany it works the way you describe: even if you get paid to do it, unless you're explicitly granting exclusive rights, you only grant a non-exclusive right. For example, if you hire a freelancer to write you software, you don't have anything other than simple usage rights unless you signed a contract with them explicitly granting you additional rights. Even if you gave them a bunch of requirements and defined deliverables. This is a case where the braindead application of existing copyright (e.g. how this works for commissioned literature) actually resulted in a good thing.