Transfer to controllers or Processors - which one to use?

I would need more information. It depends on who processes personal data. The processor collects and processes personal data on behalf of the controller, according to the article 28 GDPR. So if the contractor software company will process data on your behalf, you will be the controller and the contractor will be the processor.

On the contrary, if you are developing a software and license it to the contractor who will processes data on its own behalf and on its own servers, the contractor will be the controller and you might be the processor if you have any access to personal data (i.e. for maintenance reason).

You can also find more information here:

• EU GDPR controller vs. processor – What are the differences? https://advisera.com/eugdpracademy/knowledgebase/eu-gdpr-controller-vs-processor-what-are-the-differences/
• What is the EU GDPR and why is it applicable to the whole world? https://advisera.com/eugdpracademy/knowledgebase/what-is-the-eu-gdpr-and-why-is-it-applicable-to-the-whole-world/

You can consider enrolling in our free EU GDPR Foundations Course

• EU GDPR Foundations Course: https://advisera.com/training/eu-gdpr-foundations-course//