Understanding your Synergy bill: a complete guide for WA homeowners

A Synergy bill can read like it's in another language. Between supply charges, usage tiers, and solar credits, it's easy to lose track of where your money actually goes. Let's walk through it, section by section, until it makes sense.

The anatomy of a Synergy bill

Every Synergy bill follows the same shape. Once you know what each part is for, you can see where the savings are hiding.

Account details

Up top you'll find your account number, supply address, and billing period. The billing period matters: it sets how many days of usage you're being charged for. Most Synergy bills run for about 60 days, so they land bi-monthly.

Your tariff plan

This is one of the most important lines on the page. Synergy offers a handful of residential plans:

| Tariff | Best for | Cheap-rate window | |--------|----------|-------------------| | A1 (Home Plan) | standard households | none (flat rate) | | Midday Saver | solar households | 9am–3pm super off-peak | | Smart Home Plan (existing customers only) | EV and battery owners | overnight and weekends | | EV Add-On | EV charger households | overnight EV window |

Not sure which one you're on? Check the line-item descriptions. They'll name your plan.

Supply charge

The supply charge is a fixed daily fee you pay no matter how much power you use. Think of it as the cost of being connected. As of 2026 it's around $1.16 a day for most residential A1 customers.

Worth knowing: you can't dodge the supply charge, but knowing it helps you work out the true cost of your power. Over a 60-day billing period it adds up to roughly $70 just for the connection.

Usage charges

This is where the bulk of the bill comes from. Synergy charges for electricity in cents per kilowatt-hour (c/kWh).

On the standard A1 tariff there's one flat rate across all your usage. On time-of-use plans like Midday Saver (or the discontinued Smart Home Plan for existing customers), the rate moves with the clock:

• peak (3pm–9pm weekdays): the dearest rate
• off-peak (overnight): the cheapest
• shoulder (daytime and weekends): in between

Solar credits (REBS / DEBS)

With solar panels, you'll see credits for the energy you export. WA runs two main buyback schemes:

• REBS (Renewable Energy Buyback Scheme): the older flat buyback rate for some legacy systems
• DEBS (Distributed Energy Buyback Scheme): the current scheme, paying rates that change with the time of day

DEBS is worth understanding. Midday exports earn a lower rate (2c/kWh) while peak-window exports between 3pm and 9pm earn more (10c/kWh). That's a clear nudge to shift your solar use into the evening or store it in a battery rather than sell it cheap at noon.

GST and total

GST (10%) goes on top of your charges. Your solar credits come off first, so the GST is calculated on the net amount.

How to read your usage graph

Most bills include a graph comparing this period to earlier ones. Look for:

• seasonal patterns — summer bills run higher thanks to air conditioning
• year-on-year change — is your usage drifting up or down?
• daily average — divide total kWh by billing days for a fair comparison

Common bill surprises

Why is my bill so high?

The usual reasons a WA bill jumps unexpectedly:

1. the season — air conditioning through a Perth summer can double or triple a bill
2. an estimated read — if Synergy couldn't reach your meter, they may have estimated your usage
3. a tariff change — government rate rises happen most years, usually on 1 July
4. new appliances — pool pumps, hot water systems, and electric heating are big consumers
5. a solar fault — if your inverter has dropped out, you lose your free daytime generation

What's an "estimated read"?

If your meter reading shows an "E" or "Estimated", Synergy has guessed your usage from past patterns. The next actual read squares up any over- or under-estimate.

Spotting savings opportunities

Run through this checklist against your own bill:

Check your tariff.

• Have solar? Are you on Midday Saver, with its cheaper rates through the solar hours?
• Have an EV? The EV Add-On tariff could save you hundreds a year on charging.

Check your export credits.

• Exporting a lot of solar at the low DEBS rate? A battery could store that energy for you to use at peak times instead.

Check your peak usage.

• Heavy use in the peak window? Simple timers on pool pumps, hot water, and the dishwasher can push that load into cheaper hours.

Check for anomalies.

• Compare against earlier bills. A sudden jump with no obvious cause can flag an appliance fault or a meter issue.

Using BillWise to read your bill

Upload your Synergy bill and BillWise gives you an instant read. We'll:

• break your costs down by category
• calculate your BillWise Score (how well-tuned your energy setup is)
• point out specific savings
• compare your usage against WA averages
• suggest tariff switches, solar, battery, or electrification upgrades

Your bill already holds all the data. BillWise just reads it for you.

Next steps

1. Upload your bill to get your personalised BillWise Score
2. Compare tariff plans to see whether switching saves you money
3. Explore solar + battery options if your export credits hint at an opportunity

Ready to act? Analyse your bill now → — upload your Synergy bill and get a personalised breakdown with savings recommendations in seconds.