The duality characteristics of budgeting between the flexibility driven decision making and the integration focused management control inspire the author to investigate how the flexibility and integration domains influence business controllers? choices of IS technologies used in budgeting. This includes the enterprise resource planning (ERP) system, business intelligent (BI), web tool and spreadsheets. Guided by the concept of human agency, twenty business controllers in eleven companies in Thailand are interviewed. The analysis shows that flexibility and integration in budgeting IS technologies can be viewed from four domains: organisation-in-focus, personal requirement, business requirement and reporting requirement. The analysis also shows that there are conflicts between these four domains based on the needs for flexibility and integration. It is found that spreadsheets are used when flexibility is needed especially for decision making at local unit level. However advanced IS technologies like the ERP system, BI and web tool, are employed for relatively stable management control tasks. The major implication is that business controllers apply budgeting IS technologies to fit the nature of the budgeting tasks at hand. Therefore there is clearly a need to employ a variety of IS technologies, and not to dominate any particular IS technologies for budgeting because each system is designed for its own respective purposes and intentions.