How to read a commercial power bill in New Zealand, line by line

A business power bill is a meter record with a price list applied to it. Match each line to what it measures and a monthly check takes minutes.

What is actually on a business power bill?

There is no standard layout: the Electricity Authority says bills currently don't have to look the same or separate out charges. Its new plain-language billing standards start on 30 October 2026, but its final decision says they cover residential bills, not commercial ones.

Where is the ICP number, and why does it matter more than your account number?

The ICP (installation control point) is the 15-character identifier for your physical connection, usually printed near your account or site details. Under the Code it is a 10-digit number from the lines company, a two-character code the Authority assigns to that lines company, and a three-character checksum.

Unlike your account number, the ICP belongs to the premises and stays put when you switch, so quote it whenever you move, switch or query a charge.

Check the ICP is the site you occupy: in the Authority's billing consultation, workshop participants described a wrong address picked for a new subdivision leading to an incorrect ICP and, later, a back bill. The Authority's online ICP search finds the ICP, meter type and other connection details for any address.

With several sites, each ICP should appear once. Lines companies such as Vector charge the daily rate for every day a connection is energised, so an unused connection keeps costing until it is disconnected.

What do the meter and register numbers tell you?

The meter number identifies the device; each register records one stream of energy, such as day, night, controlled load or solar exported to the grid.

Smart meters record half-hourly use and send readings automatically, the Authority says.

Sites metered through current transformers apply a multiplier (the Code calls it ratio compensation), so billed kWh can far exceed the digits on the display. A wrong multiplier scales every unit on the bill, so confirm it whenever a meter is replaced.

How do day/night and time-of-use units work?

A unit is one kilowatt-hour (kWh): one kilowatt used for one hour. Retailers price units by time band: one anytime rate, day and night rates, or peak, off-peak and shoulder rates. Check the bands add up to the total and the hours match your agreement.

Lines companies price by time too. On Vector's Auckland and Northern networks from 1 April 2026, a small business on the "general" time-of-use lines tariff pays 10.47 cents per kWh (excluding GST) for power used 7–11am from June to August and 5–10pm from May to September, and nothing per kWh at other times. Whether your retailer passes that shape through depends on your plan.

What is the daily or fixed charge?

The daily charge is, in the Authority's words, the cost of having access to power. Multiply it by the days billed and check the period doesn't overlap your last bill.

It may include lines and metering costs. From 1 April 2026, Vector's own daily lines charge is $2.3928 for a "general" connection, excluding GST, before your retailer adds anything. For a "commercial" connection it is $5.16 on Vector's "Auckland" network; its "Northern" network prices differ.

What are lines charges, and why have they gone up?

Lines charges pay for the poles, wires and pylons of your local network and Transpower's national grid, and make up just over 30% of the average power bill, the Commerce Commission says.

Between 1 November 2025 and 30 June 2026, small business bills that changed rose 7.2% on average, and higher lines charges made up 54% of the increase across households and small businesses, the Authority reported on 12 August 2026. Vector lifted its ICP-based lines prices (excluding transmission) by a weighted average of 7.8% from 1 April 2026.

Your lines company, not your retailer, sets your price category. Vector, for example, treats non-residential connections up to 69 kVA as "general" and larger ones as "commercial". Our regional hubs show which lines companies cover each area, from Auckland to Southland.

What are demand, capacity and power factor charges?

Demand charges price your peak rate of use. They mainly apply to larger connections and are measured in kVA (or kW on some networks), not kWh. Vector's low-voltage commercial time-of-use tariff on its "Auckland" network (code ALVT) shows how they work (excluding GST and transmission). On Vector's separate "Northern" network the equivalent tariff has a $14.67 daily charge and a 0.97c volume charge, so check which network your ICP is on:

If your ten highest half-hours average 100 kVA, the demand line alone is 100 × $0.1738 × 30 = $521.40 for a 30-day month, before GST. A few busy half-hours set that figure, so staggering heavy start-ups can pay; power factor correction is an electrician's job. More in demand charges explained.

What are the EA levy, losses and GST?

• EA levy (sometimes "electricity market fee"): funds the Electricity Authority and some EECA work; the Authority puts it at about 0.4% of a typical household bill. The 2026/27 purchaser rates gazetted on 1 July 2026 add up to about $1.36 per MWh, roughly 0.14 cents per kWh.
• Losses: energy lost as heat in the lines. Lines companies publish loss factors that retailers use in pricing; Network Waitaki's low-voltage factor from 1 April 2026 is 1.055, so 1,000 kWh metered counts as 1,055 kWh. Some bills show losses separately; others build them into the unit rate.
• GST: 15% added to the total, which is about 13% of the GST-inclusive figure. GST-registered businesses can claim it back for power used in their taxable activity, so keep each bill.

Is my reading estimated or actual?

Check whether each reading is marked actual or estimated; if your bill doesn't say, ask your retailer. Estimates are corrected when a real reading arrives, which is how catch-up bills happen.

The Code requires retailers to get a validated reading for every register at least once every 12 months, and for 90% of non-half-hourly connections at each network supply point at least every four months. Repeated estimates usually mean the meter isn't communicating or can't be reached: ask your retailer to fix it, or send your own reading.

From 30 October 2026, small business consumers (defined in law as using under 40 MWh a year) can't be charged for power used more than six months before the invoice date, unless readings were missed because of the customer or vandalism, or power was obtained by deception. Catch-up amounts must come with time to pay and no interest. Larger commercial users aren't covered, so check your contract.

What three things should you check on every bill?

1. Actual or estimated? Check the reading type, dates and days billed.
2. Do the prices match your agreement? Compare each unit rate and the daily charge with your contract.
3. Does usage look like last year? Compare kWh, and peak kVA if you pay demand charges, with the same month last year. A jump with no business reason points to a fault, equipment left running or a metering error.

Once a year, request your consumption data: your retailer must provide up to 24 months, including raw meter data, free within five business days. That history shows whether your price category and capacity still suit how you use power. To have your rates compared against your actual connection, start with our savings calculator and a recent bill, or see what we do for business electricity.

What if you think the bill is wrong?

Raise it with your retailer first, quoting the ICP and bill date. If it's unresolved after 20 working days and the retailer hasn't told you in writing why it needs longer, or after 40 working days in any case, take it to Utilities Disputes. It is free and handles energy claims up to $50,000.