Recently, location-based services and applications are popular as a wireless mobile communication applications based on ubiquitous services. The location-based services and applications depend on positioning techniques such as Global Navigation Satellite System (GNSS), Wi-Fi and indoor positioning systems. Moreover, an augmentation of GNSS, such as Satellite Based Augmentation System (SBAS), improves a performance of the satellite-based navigation system through the integration of external information into the calculation process. The performance consists of accuracy, continuity, availability and integrity. In this paper, we focus on the integrity in the performance indexes of GNSS to guarantee position data against positioning deceptions and errors. Then, we propose an approach to achieve guarantee-added localization methodology using spatiotemporal contexts. Moreover, we conducted an experiment to evaluate our approach. In conclusion, we have confirmed that our proposed approach is possible to improve the integrity with some constraints for the guarantee-added localization.