Borders set the authorised limits of national sovereignty or the frontiers up to which a state may exercise its authority. In recent years, cross-border tourism has become an increasingly important economic activity between Brunei Darussalam and the East Malaysian state of Sarawak. This chapter focuses on factors influencing the frequency of cross-border tourism and investigates the cross-border shopping behaviour of Bruneian visitors crossing between Brunei and Miri in Sarawak. The surge in visits to Sarawak may have profound implications for Brunei’s revenue as high outflows of expenditure are believed to have contributed to a significant number of economic leakages. The approximate number of times people leaving Brunei was recorded as high as 2.4 million in 2018–2019, before the COVID-19 pandemic. This analysis aims to examine the purchasing patterns of Bruneian visitors as well as their motivating factors. The latter are alluded to as drivers of cross-border tourism with major reasons including price benefits, a favourable exchange rate as well as non-price factors such as the availability of choice.