The main task of the commercial division is to issue a bill with a charge based on the consumption based on the meter readings from the provision of a new water supply, and to take action to recover the water charges within 30 days. It is the responsibility of the commercial sector to provide a friendly customer service to fulfill the related customer needs.

Currently, the number of customers directly served by the board has exceeded 3.1 million and it is expected to increase to 3.3 million by the end of 2025. Out of them, 92% of the total consumers are domestic and 08% are non-domestic consumers. Domestic consumers are also divided into sub-categories such as general households, urban tenement gardens residents, and government quarters based on their nature. Commercial institutions, government schools, government offices, military stations, police stations, hospitals, religious places etc. are classified under the non-domestic category. The online billing system, which was started as a pilot project in 2024, and it has been expanded to the island wide from January 2025. Under this, instead of issuing a traditional daily bill, sending an e-bill (E-Billing) through a short message (SMS) is now being successfully carried out. Consumers have been provided with many facilities for water bill payment and the promotion of online payment has been identified as the primary goals of the year 2025. In order to encourage bill payments, consumers who pay their water bill within 14 days of receiving a 1.5% discount will be given, and if they do not pay within 30 days, a surcharge of 2.5% will be added to the bill monthly.