The Water Industry Act 1991 (“the Act”), as amended by the Water Act 2003, requires water undertakers to grant licensed water suppliers access to their supply systems under certain conditions and for certain purposes. A retail licence permits a licensed water supplier to use a water undertaker’s supply system to supply water to eligible premises of customers. A combined licence additionally permits a licensed water supplier to introduce water into a water undertaker’s supply system in order to supply that water to eligible premises of customers.