Shops in the dark over power bills

At least three big Perth shopping centres have received electricity bills from Synergy months late as further troubles with the utility's billing system become evident.

Centre manager at the Cockburn Gateway shopping centre, Leanne Chaproniere, said: "We didn't get a bill in November, we didn't get a bill in December.

"Apparently it's an issue with the (computer) program that uploads the bills between Western Power and Synergy."

Ms Chaproniere said sister centres, Belmont Forum and Mirrabooka Square, had had the same problem.

Cockburn Gateway is the smallest of the three centres, owned by the Perron Group, and pays more than $200,000 a month for electricity.

Centre managers run a system of individual meters for Cockburn Gateway's 105 tenants so those costs can be accurately passed on.

Ms Chaproniere said it was impossible to bill tenants in a timely fashion when bills from Synergy were arriving several months late.

Ms Chaproniere's complaints come as a new report from the Economic Regulation Authority details a sharp rise in complaints last financial year about billing practices, including meter readings and credit management.

Synergy had 735 billing complaints from non-residential customers in 2009-10, compared with fewer than 120 for each of the previous three years.

A Synergy spokeswoman said the billing delays were caused by a transition to a new computer system and the retailer was working with Western Power to resolve the problem.

"This issue predominantly affects a small number of large customers with a complex billing arrangement," she said.

A Catholic primary school in Inglewood received a $50,000 electricity bill last month after not getting an account for 18 months.

Shadow energy minster Kate Doust said urgent action was needed to fix the problems.

"There has been a breakdown in communication somewhere down the line and once again WA customers are being made to pay," she said.