It is a well-known feature of social protection systems that not all persons who are entitled to social benefits also claim these benefits. The costs people face when claiming benefits is considered an important cause of this phenomenon of non-take-up. In this paper, we developed and examined the psychometric properties of a new scale, the Claiming Cost Scale (CCS), which measures three dimensions of costs associated with claiming benefits. A multi-phase instrument development method was performed to develop the instrument. The item pool was generated based on a literature review, and presented to academic experts (n = 9) and experts by experience (n = 5) to assess content and face validity. In a second stage, centrality and dispersion, construct validity, convergent and divergent validity, and internal reliability of the instrument were tested. These analyses were based on two samples (n = 141 and n = 1265) of individuals living in low-income households in Belgium. Nine items were retained, which represent three factors (Information costs, Process costs and Stigma). The confirmatory factor analysis proved adequate model fitness. Both convergent and divergent validity were good, and internal consistency was adequate, with Cronbach's alpha ranging between .73 and .87. The findings showed that the CCS is a valid and reliable instrument for assessing the costs potential beneficiaries face when claiming benefits. Consisting of only nine items, the scale can be easily implemented in large-scale survey research or used in day-to-day work of service providers who are interested in understanding non-take-up of their service.