Estimated power bills are nothing new for Contact Energy customers, but they are being warned to look at their bills closely to avoid a sting when prices increase next month.
One Dunedin man said his most recent power bill was an estimate which charged him 600 units less than he had used.
He believed the estimate may have been lower because this year's winter was colder than the previous one.
At present, he paid 15.7c per kWh which would go up to 17.97c this month.
By phoning Contact and informing it of his actual meter reading, he said he had saved himself from being hit with a large bill next reading.
In order to save customers money, Contact read meters every second month; every other month, it estimated power use based on previous consumption, communications manager Jonathan Hill said.
If customers felt their energy use had changed or their estimate was inaccurate, he encouraged them to phone the call centre to inform it of their actual meter reading.
The company would be rolling out an electronic meter system over the next few years which would eliminate the need to manually read power meters, he said.
The system would send power consumption readings via electronic signal direct to the company.
Contact had started a campaign to inform its customers on the reasons behind its recent power price increases.
"We have been in the news a bit lately and people have rung to discuss current issues with us," Mr Hill said.
He said it was "fair" to say the bulk of the criticism was based on the increase in power prices and the company's annual meeting at which the fee pool for its directors was increased.
He admitted the company had lost customers because of these recent events and described it as "disappointing".
TrustPower last week confirmed 1500 of Contact's customers had switched to it.
Customers who were unsure about the reasons behind recent price increases were encouraged to contact the company to discuss what made up their bill or go to www.contactenergy.co.nz to view a brochure which outlined how New Zealand's electricity market worked.
