Water registration packs and website cost €3.2m
Irish Water has spent almost €2.4m printing and distributing registration packs - many of which are believed to have been destroyed.
The utility has distributed the packs to around two million households since last August, at a cost of around €1.18 per pack.
It spent over €810,000 on printing and related costs and another €1,550,000 on postage.
Figures released to the Irish Independent under the Freedom of Information Act also revealed that the utility's website, Water.ie, which details information on how to register with the service, has cost more than €800,000 since July 2013.
More than €450,000 of this figure was for "ongoing operational costs", according to the utility. It said it had received more than 1.1 million unique visitors, which underlined the need for a "high-end" website.
Meanwhile, logo design and vehicle branding racked up fees of €27,700 to the taxpayer.
The logo alone cost €19,400, which Irish Water said was a "12-step process carried out over a number of months" by parent company Ervia.
The utility said all costs were covered under the Irish Water establishment figure of €172.8m.