It is often taken for granted that metering is an unarguable ‘best practice’ when it comes to the quantitative management of groundwater resources. This paper revisits empirical evidence of the performance of meters on the ground, distinguishing between the logistical, financial, political and institutional factors that condition acceptability, implementation and monitoring. It is shown that metering should only be implemented when certain conditions are met. The options for technical and institutional improvements are reviewed. Then the paper turns to co-management arrangements between the state/administration and water user associations. It is argued that metering can play a key part in these arrangements rather than be, by default, an undesired nuisance. Hence, the distribution of the costs of meter installation, maintenance and monitoring should be construed as part of the balancing of costs and benefits, carrots and sticks, threats and opportunities, and of the roles of the states and water user associations. All must be designed to elicit collective action towards, and adherence to, sustainability targets.