In the title compound, C12H12O7, the dihedral angles between the benzene ring and the mean planes of the 3-carb-oxy-meth-oxy, 1-carb-oxy-meth-oxy and acetyl substituents are 8.67 (7), 7.81 (6) and 10.3 (18)°, respectively. In the crystal, mol-ecules are linked by typical carb-oxy-lic acid O-H⋯O hydrogen bonds, forming a zigzag chain. C-H⋯O inter-actions also occur.