Mostly the project charter is written by the project manager. However, there is one more key player in preparing this document which is the sponsor.

The sponsor is the main initiator and supporter of the project. This is usually a high role executive that sees real value and purpose for the project to go through. Due to their lack of time, the sponsor usually picks a project manager for the project and asks them to prepare the project charter.

Both the project manager and the sponsor collaborate on the document. The sponsor has to relay all the key information about the importance of the project and the project manager is responsible for preparing the final draft. The final approval belongs to the sponsor.

Also, if at any time, even after the project charter is completed, the sponsor feels like the project manager is not right for the job, they have full authority to choose a different person.

In some cases, the sponsor can be more than one person or even a whole team. In such situations, it is usually the group that prepares the project charter themselves. Hence project sponsor is above project manager in creating and approving the project charter.