Your TNB Bill, Line by Line

Part 3 of 7 in Cobler's Understanding Your Electricity Bill course. New here? See the course page.

Aina lays the tower's September 2026 bill on her desk, with the café owner's bill for the same month beside it. She knows where the 500,000 kWh and the 1,600 kW came from. Now she wants to follow each reading across the page to a price, and see what else is on the bill.

For a non-domestic customer in Peninsular Malaysia, the TNB bill charges come in five main lines. They are energy, capacity, network, retail and the Automatic Fuel Adjustment (AFA). A power factor surcharge is added only when the power factor is too low. After those come a renewable energy levy (KWTBB) and any tax. Almost every line is one of the meter readings from Part 2 multiplied by a price.

The café owner's bill is there as a check. It's much smaller, and if Aina can make both bills add up, she'll know she really understands them.

Tariffs

So first, which price? That depends on the tariff, the price list for the account. All prices in this course are from RP4, the TNB (Tenaga Nasional Berhad) tariff structure in force since 1 July 2025 (myTNB tariff page).

Before July 2025, a tariff was a letter. Tariff A was for homes, B for low voltage commercial premises, C1 and C2 for medium voltage commercial buildings, and D and E for industry. Under RP4, three things place each account instead:

• Voltage level: the voltage at which TNB hands electricity over to you. LV (low voltage), 400/230 V, is the supply for homes, shops and small offices. MV (medium voltage), such as 11 kV or 33 kV, is for larger buildings, malls, hospitals and factories with their own substation. HV (high voltage), such as 132 kV or 275 kV, is for very large plants close to the transmission grid.
• Sector: domestic or non-domestic. A few specific categories, such as co-generators, have their own schedules.
• Pricing option: General, with one energy rate at all hours, or Time-of-Use (ToU), with a higher rate at peak times and a lower one off-peak.

Here's where our two buildings sit:

• The office tower, Aina's building: 20 storeys, supplied at 11 kV, on the MV non-domestic General tariff. In September 2026 it used 500,000 kWh, its maximum demand was 1,600 kW and its power factor was about 0.92.
• The shoplot, the café owner's building: three storeys with a café and a small office, supplied at 400/230 V, on the LV non-domestic General tariff. In September 2026 it used 8,000 kWh.

Cobler's guide to TNB tariff categories explains how an account is placed.

A fictional sample bill, not a real TNB bill. Each charge is coloured to match the meter reading it comes from.

On the official tariff schedule, the charges have Malay names: Caj Tenaga (energy), Caj Kapasiti (capacity), Caj Rangkaian (network) and Caj Peruncitan (retail). For a tour of a real bill's layout, see how to read your TNB electricity bill.

The RP4 rates

Now for the prices themselves. These are the RP4 base rates for the four non-domestic categories that most buildings fall into. The rest of the course keeps coming back to this table.

Three things in the table need a word of explanation:

• On a ToU tariff, the peak window is 2pm to 10pm, Monday to Friday. All other hours are off-peak, and weekends are off-peak throughout.
• On the MV tariffs, capacity and network add up to RM89.27 per kW on General and RM97.06 per kW on ToU. On MV General, maximum demand counts at any hour, and on MV ToU only demand inside the peak window is charged. These totals don't apply to HV or special categories, which have their own rates.
• The energy, capacity, network and retail rates are the base tariff, fixed for the whole RP4 period, 1 July 2025 to 31 December 2027. The one line designed to change every month is the AFA, which we'll get to below.

Energy charge

So let's start at the top of Aina's bill. The energy charge is the kWh multiplied by a rate in sen per kWh. Rates are quoted in sen, and 100 sen make RM1, so the last step is to divide by 100.

• Aina's tower (MV General): 500,000 kWh × 29.83 sen = 14,915,000 sen = RM149,150
• The café owner's shoplot (LV General): 8,000 kWh × 27.03 sen = 216,240 sen = RM2,162.40

On a ToU tariff, the meter splits the kWh into peak and off-peak, and each part is charged at its own rate. Both our buildings are on General tariffs, so each has one energy rate for every hour. Part 5 looks at whether switching to ToU would pay.

Capacity and network charges

The next two lines are where the two bills start to differ. The capacity charge pays for generating capacity kept ready for your highest demand. The network charge pays for the transformers and cables that deliver it. That equipment has to be sized for the peak, not the average. So how these two lines are billed depends on the supply voltage.

On an MV tariff, they're charged per kW of maximum demand. For Aina's tower, the highest half hour of September was 2:30pm to 3:00pm on a hot weekday, at 1,600 kW:

• Capacity: 1,600 kW × RM29.43 = RM47,088
• Network: 1,600 kW × RM59.84 = RM95,744

Together that's RM142,832, nearly half of the tower's bill, and a single half hour set it. On MV General, that half hour could have fallen at any time of day or night. On MV ToU, only the weekday peak window counts, which Part 5 explains. And Part 4 looks at what sets the tower's 1,600 kW, and how to lower it. To put a price on your own building's peak, try our maximum demand calculator.

On an LV tariff, they're charged per kWh instead. For the café owner's shoplot:

• Capacity: 8,000 kWh × 8.83 sen = RM706.40
• Network: 8,000 kWh × 14.82 sen = RM1,185.60

So that's why the shoplot's bill has no per-kW charge. The shoplot still has a busiest half hour in the month, and that peak still loads TNB's network. But the LV tariff recovers the cost of capacity and network through each kWh, so the bill has no maximum demand line. For the café owner, these two lines only go down when the kWh go down, and lowering the peak alone doesn't change them.

Retail charge

The retail charge is the simplest line on the bill, a flat fee for having an account. It pays for billing, metering and customer service, and it doesn't depend on any meter reading.

• MV: RM200 a month (Aina's tower).
• LV: RM20 a month (the café owner's shoplot).

The AFA

The next line is the only one that moves every month. Much of Malaysia's electricity is generated from gas and coal, and fuel prices and the ringgit exchange rate keep changing. The Automatic Fuel Adjustment (AFA) passes the difference between the actual fuel cost and the cost assumed in the base tariff on to the bill. It's a rate in sen/kWh, set each month, and it can be a surcharge that's added or a rebate that's taken off. So always check which month an AFA figure belongs to.

For September 2026, the AFA is a surcharge of +3.67 sen/kWh, multiplied by the kWh:

• Aina's tower: 500,000 kWh × 3.67 sen = 1,835,000 sen = RM18,350
• The café owner's shoplot: 8,000 kWh × 3.67 sen = 29,360 sen = RM293.60

In another month, the same kWh could give a different AFA line. Cobler's AFA explainer tracks the monthly rates.

Worth knowing: The energy, capacity, network and retail rates stay the same until 31 December 2027. So say the tower uses the same kWh and sets the same maximum demand in two different months, but the bills differ. Then the AFA line is the first place to look, because it's the only line built to move every month.

Optional detail: Before July 2025, fuel costs were passed on through the ICPT (Imbalance Cost Pass-Through), which was reset every six months. For July to December 2024, for example, the ICPT was a surcharge of 16 sen/kWh for medium and high voltage commercial and industrial customers. For low voltage commercial customers it was 2.70 sen/kWh (TNB ICPT FAQ, July to December 2024). The monthly AFA replaced it.

Power factor surcharge

Now there's one line that Aina's bill doesn't have. If the power factor, the meter's third reading from Part 2, falls below TNB's minimum, a surcharge is added to the bill. Part 6 explains power factor, the surcharge rule and how capacitor banks avoid it.

Aina's tower runs at about 0.92, thanks to its capacitor banks, which is above TNB's minimum. So its bill has no power factor surcharge, and the café owner's September bill has no power factor line either.

KWTBB and tax

After the main charges come the levy and the tax. KWTBB stands for Kumpulan Wang Tenaga Boleh Baharu, the Renewable Energy Fund. The levy is collected on the TNB bill and pays for renewable energy programmes. It's 1.6% of the kWh and kW charges, about RM1.60 for every RM100 of those charges. Some accounts are exempt or have the levy waived, so check the KWTBB line on your own bill. Cobler's KWTBB guide explains who pays it and when it's waived.

Tax may also appear, depending on the account. Our worked examples stop before KWTBB and tax, so the totals in this course are always "before KWTBB and tax".

Both bills

So let's put the two September 2026 bills side by side, before KWTBB and tax.

The same five lines on two bills. For the office tower, capacity and network follow its peak kW. For the shoplot, they follow its kWh.

Now look at the café owner's column. Every line except retail is a rate per kWh, so the whole LV bill fits in one formula. We add the four per-kWh rates, multiply by the kWh, and add the retail charge:

$$\text{Bill} = \big(r_{\text{energy}} + r_{\text{AFA}} + r_{\text{capacity}} + r_{\text{network}}\big) \times \text{kWh} + \text{Retail}$$

With the rates in RM per kWh:

$$\text{Bill} = (0.2703 + 0.0367 + 0.0883 + 0.1482) \times 8{,}000 + 20 = \text{RM}4{,}368.00$$

No single formula like this works for Aina's bill, because two of its lines follow kW instead of kWh.

Dividing each total by the kWh gives the effective rate, the average cost of one kWh:

• Aina's tower: RM310,532 ÷ 500,000 kWh ≈ 62.1 sen/kWh.
• The café owner's shoplot: RM4,368 ÷ 8,000 kWh ≈ 54.6 sen/kWh.

But be careful with that average. It doesn't tell us what one saved kWh is worth on the tower's bill, because the capacity and network lines don't fall when kWh fall. Part 7 works out what a saved kWh is really worth on each bill.

So the two bills respond to different things. For the tower, nearly half the bill comes from the maximum demand, so one busy half hour matters a great deal. For the café owner, every line except the RM20 retail charge follows the kWh, so using less energy is what lowers the bill.

The half hour

Aina can now explain every line of her bill to the owner, from the meter reading behind it to the rate it uses. She can also say why the café owner's bill works differently. But one pair of lines stands out. The capacity and network charges, RM142,832 together, nearly half the tower's bill, were set by a single half hour on one hot afternoon.

It's the first thing the owner will ask about. How can 30 minutes cost that much, and what can the tower do about it? We'll take that half hour apart in Part 4: Maximum Demand: Why One Bad Half-Hour Costs So Much.

Check your understanding

1. Why does the café owner's bill have no per-kW charge, when Aina's tower bill does?

2. The café owner's whole bill can be written as one rate per kWh times the kWh, plus RM20. Why can't Aina's bill be written that way?

Recap

• Under RP4, an account is placed by voltage level, sector and pricing option.
• A non-domestic TNB bill has five main lines, and almost every one is a meter reading multiplied by a price.
• The energy charge is kWh × a sen/kWh rate. On ToU it splits into peak and off-peak, with the peak window 2pm to 10pm on weekdays.
• Capacity and network are charged per kW of maximum demand on MV tariffs, and per kWh on LV tariffs.
• On MV, capacity and network come to RM89.27/kW on General, counted at any hour, and RM97.06/kW on ToU, peak window only.
• The retail charge is fixed, and these base rates hold until 31 December 2027.
• The AFA is kWh × a rate that changes monthly (+3.67 sen/kWh in September 2026).
• A power factor surcharge is added only below TNB's minimum. KWTBB is 1.6% of the kWh and kW charges, and tax may follow.
• Aina's tower bill for September 2026 comes to RM310,532 before KWTBB and tax, and the café owner's comes to RM4,368.

This is Part 3 of 7 in Cobler's Understanding Your Electricity Bill course. Previous: How Electricity Meters Work: Disc to Smart Meter. Next: Maximum Demand: Why One Bad Half-Hour Costs So Much.

Cobler builds CobiNeural, a platform that shows a facility team its building's energy, water and indoor air data as live numbers across the whole site. Equalbase, for example, watches maximum demand at each of its warehouses during the month instead of finding it on the TNB bill. To see how your building performs, talk to us.