3.13. I have started development of a product using the open source version of Qt, can I now purchase a commercial version of Qt and move my code under that license?
Products distributed under the commercial version of Qt must also be developed under the commercial version of Qt.
If you have already started the development with an open-source version of Qt and wish to move to a commercial license you need to have a written explicit permission from The Qt Company to facilitate this change. The Qt Company reserves the right to grant the permission at its own discretion.
If you are unsure of which license or version to use when you start development, we recommend you contact The Qt Company to advise you on the best choice based on your development needs.