This study examined the effect of prepayment gas meters (households pay for their gas as they use it) as a feedback instrument on gas consumption by households. Furthermore, behavioral determinants of the reduction in gas consumption were studied. Half of the households in the experimental group were issued a notebook allowing them to compare their gas consumption with a self-set goal. The results revealed that households with a prepayment meter reduced their annual gas consumption by 4.1% compared with the control group; the notebook did not result in additional savings. Furthermore, changes in objective gas consumption were related to self-reported changes in intention toward reducing consumption.