The budget is used in many organizations to estimate and control costs. The budgeting process requires extensive knowledge and information exchange between the budget setters in the organization. It is therefore critical for budget setters, often finance and line managers, to communicate and exchange knowledge to reach a budget for the upcoming period.   The aim of this thesis is to highlight both budgeting and internal communication findings from past research, and develop a model for how internal communication is affected by different factors during the budgeting process. Specifically, we develop an unprecedented model based on previous research and test it through qualitative semi-structured interviews. We then improve and develop the model to provide a theoretical framework for future research on factors affecting internal communication during the budgeting process.   Our empirical study of communication between line managers and finance managers in GE Healthcare in their budgeting process indicates that the factors are intertwined, and that the various factors can affect internal communication during the budgeting process directly and indirectly.  The factors we find to directly affect internal communication are geographical distance, interpersonal relationship, communication method, organizational distance and characteristics of the budgeting process. The indirect factors are characteristics of the participant and time constraint. The study also finds a series of interconnected relationships of both the direct and indirect factors with each other.