Fluctuations in the network pressure of water supply systems affect hydraulic performance and water meter accuracy. The development of metering error curves requires steady-state conditions which are extremely rare in water distribution systems characterized by intermittent supply. Simple deterministic models are suggested and developed from monthly data collected over a 4-year period (2010–2014) for three most dominant meter models (Models 1–3) in the Kampala Water Distribution System (KWDS), Uganda. This study combines pressure and billing information at the same time to understand metering accuracy. Results showed that metering accuracy increased by 4.2, 8.4 and 2.9% when pressure was increased from 10 to 50 m for Models 1–3, respectively. Age did not influence the impact of pressure on meter accuracy. The most sensitive parameter in the model was the meter age. Metering accuracy was relatively constant after a period of 5 years. The least sensitive parameter was the working pressure which caused a slight change to the annual billed volume. The ability of the model to accurately predict the meter registration degenerated with an increasing annual billed volume. Model 2 meters were the best performing and probably the most suitable meters in the KWDS.
Working pressure showed a positive effect on meter registration which degraded with aging.
Low median working pressure caused an increase in meter under-registration.
Meter age was the most sensitive parameter.
The ability of the model to accurately predict the meter registration degenerated with an increasing annual billed volume.
Model 3 was the best meters in the system.