We analysed the use of professional representative services and related outcomes in patent, utility model, design right and trademark filings. We found that: 1) there is a positive association between the use of a professional representative and the likelihood of grant or registration; 2) the demand for professional intellectual property rights (IPR) services is heterogeneous between IPR types: applicants are most likely to hire professional representatives (IPR agents and attorneys) for patents, followed by utility models, design rights and trademarks; 3) individual applicants are less likely to use professional representatives compared to firm applicants.