> ## Documentation Index
> Fetch the complete documentation index at: https://docs.termina.com/llms.txt
> Use this file to discover all available pages before exploring further.

# How rates are costed

> How Termina costs business electricity plans: annual usage, time-of-use and demand charges, GST, and how each plan is compared with the Default Market Offer or Victorian Default Offer at the same usage.

Every plan is costed for a full year at the same usage, so plans are directly comparable.

## Usage

`usage_kwh` sets annual usage. It defaults to **10,000 kWh**, the reference usage the AER and ESC use for small business standing offers, and `usage.default_basis` tells you whether a default was used.

For time-of-use plans, usage is split into peak, shoulder and off-peak using `peak_share` and `shoulder_share` (the rest is off-peak). For demand tariffs, `max_demand_kw` sets the demand that's charged. If you don't pass these, typical values for the network are used and an `illustrative_profile` warning says so.

## Annual cost

Each plan's `annual_cost_inc_gst` is:

* the daily supply charge for 365 days, plus
* usage charges for each period at its share of annual usage (stepped rates are currently costed at their first step), plus
* demand charges at `max_demand_kw`, where the plan has them,
* less percentage discounts published with the plan, including conditional ones such as pay-on-time discounts,
* with GST included.

Rates in the response are in cents incl. GST: `peak_c_per_kwh_inc_gst` (or the single rate for flat plans), `shoulder_c_per_kwh_inc_gst`, `off_peak_c_per_kwh_inc_gst`, `supply_c_per_day_inc_gst`, and `demand_per_kw_per_year_inc_gst` in dollars.

## Benchmarks

Each network's regulated standing offer is costed from its published unit prices at **the same usage as the plans**, so the comparison is like for like.

| Networks | Benchmark | Source |
| - | - | - |
| Ausgrid, Endeavour Energy, Essential Energy, Energex, SA Power Networks | Default Market Offer (DMO) | AER 2026-27 determination, small business flat rate tariff caps |
| CitiPower, Powercor, Jemena, United Energy, AusNet Services | Victorian Default Offer (VDO) | ESC 2026-27 small business flat tariffs |
| TasNetworks | Aurora Energy regulated tariff | Aurora Energy Tariff 23, 2026-27 |
| Evoenergy (ACT), Ergon Energy | None | No benchmark with published unit prices |

`vs_standing_offer_pct` on each plan, and `vs_benchmark_pct` in `summary`, give the difference in %. Negative means cheaper than the standing offer. `benchmark.published_reference` holds the regulator's own headline figure, for checking against the source.

## Data and freshness

* **Public plans:** retailers' published business plans under the Consumer Data Right, the data behind Energy Made Easy.
* **Buying group rates:** Termina's negotiated offers.
* **Postcodes and cities:** postcode coverage published with retailers' plans, and ABS (ASGS 2021) geography.

Rates are checked daily and API responses are cached for up to an hour. Benchmarks are updated each July when the regulators publish new prices.

## Limits

The costing uses the usage and shares you provide. A business's real bill also depends on its meter, any controlled load, solar exports and its actual time-of-use pattern, so treat results as a comparison, and confirm against the business's bill before switching.


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