500 Riyals

The 2016–2017 500 Riyal note belongs to the series introduced partly in response to updated security standards that the earlier issues — running back to the 1980s De La Rue relationship — were no longer meeting. Thomas De La Rue has printed Saudi currency for decades, a commercial arrangement that has outlasted multiple Saudi governors and several significant oil-price shocks.

Pick 42 lists watermarking as the primary cited security feature, which undersells what De La Rue typically incorporated into Saudi high-denomination production by this period, though catalog documentation for the full security specification on this issue remains incomplete in most reference sources.