This study focuses on developing a strategic management tool for small and medium-sized enterprises (SMEs), where outsourcing is seen as an effective method. Outsourcing allows SMEs to concentrate on their core strengths and compete despite limited resources. In Vietnam, SMEs make up over ninety percent of all businesses and play a key role in the economy. However, they face challenges due to limited resources, especially in managing accounting functions. This research examines the factors influencing the level of outsourcing among SMEs in Vietnam based on two key theories: Transaction Cost Theory (TCE) and the Resource-Based View (RBV). A sample of 236 questionnaires was analyzed using SPSS and regression models. The findings revealed positive and significant relationships between outsourcing intensity (OS.Intensity) and four factors: asset specificity (AS), frequency of accounting tasks (FREQ), trust (TRUST), and technology competence (TECH). The study supports the trend of accounting outsourcing for Vietnamese SMEs, allowing them to enhance their internal strengths despite resource constraints. Future research to gain a deeper understanding of accounting outsourcing is also suggested.