If you need to call Prime Water, a Manny Villar company, don’t waste time like I did calling the number printed on the bill. Instead call this number – 02 7279173. And if you wish to pay the bill online, don’t use the account number field of the bill. Instead, use the ATM reference number.
You can also get an electronic copy of your bill by sending an email to firstname.lastname@example.org. Provide them your account number and they will reply back. One is only left to wonder why they don’t make this a proper online electronic bills service rather than something adhoc like this and using a gmail address.
They also clearly want to make payment painful if you are paying late. Bills cannot be paid online if you are paying late. There is a workaround however, if you realise the last 4 digits of ATM phone reference are month+date of bill due. You can tweak the last 4 digits so they are a future date in case you want to pay prime water bill online. Tested working via Citibank PH online bill payment.