How a Kiwi company received an $18,481 energy bill

New Zealand's lack of "back-billing" rules has left a small business with an electricity bill of over $18,000. 

The enormous bill was brought to the attention of the dispute resolution service Utilities Disputes by the business owner, who says she received a bill for $18,481.27, Stuff reports. 

The unnamed energy company said it hadn't billed the woman's business correctly for three years, and that the huge bill was issued to make up for those mistakes. 

This is allowed in New Zealand, where there is no limit for catch-up energy bills.  

In Australia the back-billing limit for energy companies is nine months, while the UK has a 12-month limit.  

Utilities Disputes commissioner Nanette Moreau told Stuff energy companies shouldn't be making mistakes because of "smart meters, which feed customer power usage data automatically to electricity providers."

The business owner agrees, saying energy companies should be held responsible for their billing errors - not the customer. 

But in this case, the energy company's terms and conditions allowed it to charge the customer for estimated use. There were no time limits on back-billing. 

Utilities Disputes is a free service that deals with complaints from consumers about electricity and gas companies. advises people to check their power meters regularly, because while energy companies bill their customers monthly, they usually only send someone around to read the meter every second month.  

In each intervening month they send you an estimated account, based on your consumption over the previous years.

If you have good reason to think the estimated account is too high, you can send a cheque to the company for what you think is fair, together with an explanation. 

"If you know how, you could read the meter yourself," says.  

"Many electricity companies let you tell them the meter reading and they will send out an accurate bill."