5-hydroxymethylfurfural (HMF) is one of the most promising platform molecules, and can be converted into a variety of interesting chemicals. The production of HMF is essentially targeted at bulk chemicals downstream, such as chemicals for the fuels and plastics industries. One critical challenge in HMF production processes is the link to further value-adding reactions in a simple and efficient way (e.g., fewer isolation and purification steps). Herein, a novel poly-benzyl ammonium chloride (PBnNH3Cl) resin is developed as a highly efficient and stable catalyst for dehydration of carbohydrates into HMF. In the isopropanol system, PBnNH3Cl produces high purity HMF that is suitable as feedstock for oxidation to 2,5-furandicarboxylic acid (FDCA). The excellent catalytic properties together with its easy synthesis, low cost, and nontoxic nature make this poly-ammonium resin a promising catalyst for the development of new and efficient processes for biomass-based chemicals.