This study proposes a procedure for defining, assessing and classifying free or payable complementary hotel services. These services are susceptible of being provided to holiday hotel tourists at mature sun-and-sand destinations to increase guest satisfaction and hotel profitability. Following this procedure, an empirical study was carried out, by means of in-depth interviews, Delphi's methodology among experts on tourist hotels, and a survey, which was distributed to a sample of 1100 tourists. As a result, a set of complementary services was obtained. These services may be (1) dispensable or susceptible of being eliminated or reduced due to their low importance and frequency of use, (2) essential, as they must be provided because they are very relevant and frequently used, and (3) desirable, because they must be provided due to their high relevance for tourists.