H-1 NMR spectrometry and X-ray diffraction were used to investigate supramolecular complexes of bambusurils and dialkyl phosphates. It was shown that bambusuril forms external complexes of 1:1 stoichiometry with dialkyl phosphates in chloroform solution. Conversely, a 2:1 complex was observed in the solid state in which each of the opposed macrocycle portals is occupied by one phosphate anion. Exclusive preference of external over inclusion binding of organic phosphates with bambusuril precludes these complexes to be used for the preparation of interlocked structures.