According to the PMBOK Guide, the project manager should follow the change management process to handle any change request, regardless of the source or nature of the change. The change management process involves identifying, analyzing, documenting, presenting, deciding, communicating, and implementing the change request. The first step in this process is to validate the proposed change’s impact on the project, which means assessing how the change would affect the project scope, schedule, cost, quality, risk, and other aspects. This would help the project manager to determine the feasibility, desirability, and priority of the change request, and to prepare a recommendation for the change control board (CCB). The project manager should not check the budget, accept, or refuse the change request without validating its impact first, as these actions would bypass the change management process and could lead to negative consequences for the project. References:

PMBOK Guide’s Change Management Process For PMP Exam

Change Management Process for Project

Managing Change in Organizations: A Practice Guide