The ion exchange reactions ofn-butylamine intercalates of tin(IV) hydrogen phosphate and hydrogen uranyl phosphate towards carbonatotetraamminecobalt(III), chloropentaamminecobalt(III), and hexaamminecobalt(III) have been investigated. Independent of the complex cation charges, the amounts of Co(III) complex exchanged by then-butylamine intercalate of tin(IV) hydrogen phosphate are practically the same. With then-butylamine intercalate of hydrogen uranyl phosphate, the ionic exchange was completed and the composition was fixed by the exchanged Co(III) complex. The layer charge densities of these phosphates justify the different ionic exchange behaviour observed towards the large complex cations. All the products were characterized by chemical analysis, X-ray diffractometry, infrared spectroscopy, diffuse reflectance spectroscopy, and thermal analysis.