Electric bill terms, explained

18bill terms explained, with a real tariff behind each where one exists

This glossary covers every line the decoder reads. The right-hand column draws on 369 residential tariffs from 111 utilities, taken from the OpenEI database as of 17 April 2026.

Bill terms and what to check

Electric bill terms, plain meaning and examples from the tariff snapshot
Term	What it means	Where you see it	In the tariffs on file
Customer charge (basic service, facilities charge)	A fixed monthly fee for the meter, the service line and billing. You pay it at zero kWh.	Top of the bill, before usage lines.	Lowest in this set: $0.00 (Austin Energy). Highest: $253.68 (Mississippi Power Co).
Energy charge	The price per kWh for the electricity you use. On a bundled tariff it covers supply and the wires together.	A usage line, kWh times rate.	369 tariffs in this set; the decoder prices each.
Tier or block	A rate that changes after set amounts of monthly use. Usually the price rises with use; some utilities reverse it.	Several energy lines, each with a kWh range.	Widest step: Public Service Co of NM, where the top tier costs 1.8 times tier 1.
Time-of-use (TOU) rate	The price depends on the hour and sometimes the day. Peak hours cost more, off-peak hours cost less.	Energy lines labelled on-peak, off-peak or by period.	Largest spread here: Evergy Metro, 11.0 to 1 between its most expensive and cheapest hours.
Seasonal rate	Energy rates differ in summer and winter, often because summer demand is costlier to serve.	The same line with a different rate in some months.	Largest swing here: Southwestern Public Service Co, 55% between the most expensive and cheapest season.
Minimum bill	A floor on the monthly total. It matters only when fixed plus energy would fall below it.	May show as a minimum charge or a 'minimum bill' note.	15 of the 369 tariffs list one.
Demand charge	A price per kW of your highest use in a short window. Common for businesses and a few residential plans.	A line in kW, not kWh.	66 of the 566 bundled residential plans effective since 2023 carry one. The decoder leaves those plans out, so it never guesses your kW.
Delivery (distribution)	The wires, poles, meters and crews that bring power to your home. Charged by the wires company.	A delivery line, or inside the energy rate on a bundled tariff.	280 of 846 plans in the snapshot are delivery-only tariffs; the supply is bought elsewhere.
Supply (generation, commodity)	The electricity itself, bought by the utility or by a retail supplier you picked.	A supply or generation line; in deregulated areas it can come from another company.	Shown separately only where the bill is split.
Transmission	High-voltage lines that carry power from plants to local wires.	Often a rider or folded into delivery.	Not a separate row in most URDB rate tables.
Fuel or power-cost adjustment	A pass-through that moves with fuel and purchased-power costs. It can rise or fall each month or quarter.	Per-kWh line, often small and changing.	Outside the rate table in most records; one reason a bill runs above the tariff.
Rider or surcharge	A line approved by the state commission for a program: efficiency, storm recovery, renewables, low-income help.	Short named lines, per kWh or fixed.	Same: usually not in the rate table.
Taxes and franchise fees	State and local taxes, plus a fee the city charges the utility to use its streets, passed on to customers.	Bottom of the bill.	Never in the tariff rates.
Net metering credit	A credit for solar power you send to the grid, applied against what you use.	A negative kWh or dollar line.	Plans built for solar are left out of the main utility pages.
Bundled and unbundled	Bundled: one tariff covers supply and delivery. Unbundled: they are separate lines, maybe from separate companies.	One energy line, or two sets of lines.	Decoder covers bundled tariffs: 405 of the 566 bundled plans fit its model.
Billing days and estimated reads	A cycle is 27 to 33 days, not a calendar month. An estimated read means the meter was not read and kWh is a guess.	Dates and 'estimated' near the usage.	Compare kWh, not dollars, across cycles of different length.
Per-day fixed charge	Some utilities set the customer charge per day, so it rises in longer cycles.	A line with a day count.	56 of the 369 tariffs state it per day; we convert at 30.4 days.
Budget billing	The bill is set to a flat yearly average and reconciled later. It hides month-to-month swings.	A plan note and a true-up amount.	Not a tariff rate; the decoder reads actual bills, not budget amounts.

Reading a bill in four steps

Find the kWh used and the dates of the cycle.
Find the fixed charge. It is the same in every month.
Add the energy lines. Check whether tiers or hours apply.
What is left is riders, adjustments, taxes and fees. Ask the utility for each name.

What the decoder covers

Tariff types among the plans the decoder prices
Tariff type	Plans on file	Share
Flat energy rate	86	23%
Tiered energy rate	95	26%
Seasonal energy rate	42	11%
Time-of-use energy rate	146	40%

Sources

Tariffs: OpenEI Utility Rate Database, snapshot of 17 April 2026, CC BY 4.0.
Download: decode_tariffs.csv.

Keep going

Questions

Why does the decoder skip plans with a demand charge?

A demand charge needs your highest kW, which a bill rarely shows. 66 of 566 bundled plans since 2023 have one, so we leave them out rather than guess.

What is the difference between delivery and supply?

Delivery is the wires side, supply is the energy itself. In the snapshot 280 of 846 residential plans are delivery-only, so the supply price is set elsewhere.

Why do my kWh and my neighbor's differ on the same day?

Billing cycles start on different days, run 27 to 33 days, and some reads are estimated. Compare kWh per day, not per cycle.

Is the customer charge the same all year?

Usually yes. Among the 369 tariffs here the customer charge runs from $0.00 to $253.68 a month.

Where do fuel adjustments appear?

As a separate small per-kWh line, or inside the energy rate. They change by month or quarter, so they explain part of the gap between a tariff and a bill.