Spatial CGE models rely on detailed information from multiregional input-output systems. Multiregional input-output tables (IOT) are usually not available and have to be compiled. This paper compares two different approaches to compile regional IOT – algorithm based approach that mechanically regionalizes national IOT using a predefined set of regional variables and hybrid approach that uses as much regional data as possible. We aim at verifying whether a use of a given approach has a significant impact on CGE simulation results. In our case, we compile regional IOT for Austria applying ready-made Horridge algorithm and a hybrid approach. We find that aggregate simulation results are surprisingly similar. As a result, we could claim that algorithm based approach is in fact an effective way of regionalizing national IOT. However, once we compare the results at the sectoral level they start to differ significantly. This may raise serious concerns about the adequacy of certain results based on ready-made disaggregation models.