Quick Answer
A minimum bill is the least you owe for service in a billing period no matter how little you use — if usage charges fall below the tariff’s stated floor, the floor is what you pay. Rate schedules write it as a “Minimum Charge” or “minimum monthly charge.”
Decision rule: before calling a tiny-usage bill a billing error, check the rate schedule for a Minimum line.
Published minimum-charge clauses (real tariffs)
| Tariff | Service class | Verified language and amounts |
|---|---|---|
| Avista Schedule 1 (WA residential electric) | Residential | Monthly rate: $10.00 Basic Charge plus energy per kWh; “Minimum Charge: $10.00” [1] |
| Avista Schedule 11 (WA general service) | General service | $30.00 Basic Charge plus energy and demand; “Minimum: $30.00 for single phase service and $37.35 for three phase service,” unless a contract requires more [2] |
| PG&E gas Schedule G-1 (CA) | Residential gas | Minimum Transportation Charge of $0.13151 per day — the Transportation Charge “will be no less than” that amount [3] — about $4.08 across a 31-day month (0.13151 × 31) |
| PG&E electric, EM/EM-TOU (CA) | All-electric residential | Delivery Minimum Bill of $0.41373 per meter per day, with a CARE discount [4] |
Avista’s residential minimum equals its basic charge: at the $10.00 floor with 0 kWh delivered, the bill is $10.00. A 20-kWh month bills $10.00 + (20 × $0.10322) = $12.06, clear of the floor [1]. PG&E’s G-1 floor scales with the days in the cycle rather than a flat monthly number [3]. Both shapes exist; your tariff decides which one bills you.
Why a near-zero month still bills
Service costs whether energy flows or not — lines, meter, billing, support. Two mechanisms cover it:
- A flat fixed charge every month — the customer charge. On tariffs like Avista Schedule 1, that fixed charge is the minimum [1].
- A stated minimum applying when usage charges run thin — the shape of Avista’s general-service Minimum and PG&E’s per-day minimums [2][3][4].
Many residential schedules carry no separate minimum clause; the always-on fixed charge plays the floor’s role — SMUD’s residential schedule prices a monthly fixed charge with no minimum-bill clause in the rate table. PG&E went the other way in March 2026: its Base Services Charge “replaces the monthly Minimum Electric Charge” [5], so the floor now appears as the fixed-charge line.
How to check the floor on your account
- Confirm the period: the cycle’s day count and meter status print on the statement; PG&E-style per-day minimums multiply by those days [3][4].
- Pull the rate schedule for your class and look for a line named “Minimum,” “Minimum Charge,” or “minimum monthly charge” [1][2].
- Read its scope — total bill, delivery-only, or one component. PG&E’s minimums are scoped by schedule and customer class, with some groups exempt [3][4].
- Recompute the floor: Avista-style is a flat monthly number; PG&E-style is per-day × days in cycle. Compare with the billed amount.
- If billed > floor + usage math, review the full line-item breakdown before disputing — riders, taxes and fees, or an estimated read can explain the gap.
For a move-out period, the floor interacts with proration — a short final bill can prorate the fixed charge while the minimum clause still governs the least you can owe.
