A new sulfate acid polymorph of 1, 3-dihydrobenzotriazole, viz. 1, 3-dihydrobenzotriazolium hydrogensulfate, C6H6N3+· HSO4−, differs from an existing polymorph in that the polymeric interaction between the HSO4− anions, together with different classical (D—H⋯ A) and nonclassical (C—H⋯ A) interactions, changes the space group.
