How to Read Your Hydro Bill in Ontario
Quick breakdown
- Energy (kWh): The electricity you used during the billing period.
- Price plan: Ontario bills usually use TOU, ULO, or Tiered rates set by the Ontario Energy Board (OEB).
- Delivery + regulatory: Charges tied to local wires, system operation, and market programs.
- Taxes and rebates: HST applies, and eligible accounts may show the Ontario Electricity Rebate (OER) line.
This page is Ontario-specific. For Quebec, see How to Read Your Hydro-Quebec Bill (Rate D).
Step 1: Identify your Ontario price plan
Look for a section that identifies your electricity price plan. Most Ontario residential bills are on one of these OEB plans:
- Time-of-Use (TOU): different prices by time period (off-peak, mid-peak, on-peak).
- Ultra-Low Overnight (ULO): very low overnight price, but a high weekday on-peak window.
- Tiered: one price up to a monthly threshold, then a higher price above that threshold.
As of November 1, 2025, OEB residential reference prices are TOU: 9.8 / 15.7 / 20.3 cents per kWh (off/mid/on), ULO overnight: 3.9 cents per kWh, and Tiered: 12.0 then 14.2 cents per kWh (with seasonal threshold changes). Always verify the latest OEB table before publishing rate-sensitive calculations.
Step 2: Understand what each bill line means
Ontario bills are usually grouped into a few major sections:
- Electricity: your metered kWh multiplied by your active price plan.
- Delivery: distribution and transmission related charges from your local utility and the broader grid.
- Regulatory: costs to operate and administer Ontario's electricity system.
- Rebate line: eligible accounts may show OER as a separate credit.
- HST: tax applied after applicable adjustments.
If your total jumped, compare both usage and each charge category, not just the final amount. A higher total can come from increased kWh, a plan mismatch (for your usage habits), seasonal threshold shifts, or delivery and tax impacts.
TOU vs ULO vs Tiered: practical decision rule
| Plan | Works best when | Risk area |
|---|---|---|
| TOU | You can shift some use to evenings/weekends. | Weekday on-peak usage can still raise costs. |
| ULO | You can move heavy loads to 11 p.m. to 7 a.m. (EV charging, laundry). | Late afternoon/evening weekday usage can be expensive. |
| Tiered | Your usage timing is fixed and you prefer predictable rates. | Crossing monthly threshold pushes additional kWh to the higher tier. |
If you have an EV and can charge overnight, ULO can be strong. If your household load is concentrated in weekday evening hours, TOU or Tiered may be better depending on your monthly kWh profile.
Step 3: Estimate your next Ontario bill
- Get your recent daily or monthly kWh usage from your bill history.
- Apply your current Ontario plan (TOU, ULO, or Tiered) to energy usage.
- Add delivery and regulatory lines from a recent statement as a planning baseline.
- Apply HST and include rebate lines where eligible.
Use the kWh Calculator and Electricity Cost Calculator for appliance-level estimates, then reconcile against your utility statement structure.
Ontario troubleshooting checklist for high bills
- Did your billing period have more days than last cycle?
- Did your price plan change or stop matching your usage pattern?
- Did seasonal heating/cooling loads increase your kWh?
- Did EV charging move into higher-cost windows?
- Did delivery and HST rise even with similar energy usage?
For utility-specific context, Toronto Hydro's high-bill guidance highlights seasonal HVAC impact, phantom loads, and billing-cycle day count variation as common causes.
Related tools and guides
FAQ
Where do I confirm current Ontario electricity prices?
Use the Ontario Energy Board electricity rates page. It publishes current TOU, ULO, and Tiered prices and seasonal thresholds, plus links to historical rates.
Does delivery disappear if I lower usage?
Not entirely. Some delivery components vary with usage and some are fixed. Even low-consumption months typically retain baseline delivery and regulatory charges.
Is ULO always cheapest?
Only for the overnight window. ULO also has a high weekday on-peak period. It helps most when you can shift large flexible loads to overnight hours.
Why did my bill rise with similar usage?
Check billing days, plan mix, delivery components, and tax/rebate lines. A longer cycle or changed charge mix can increase totals even when kWh is similar.
Can I switch between TOU, ULO, and Tiered in Ontario?
Residential and eligible small business customers can generally choose among OEB-regulated plans through their local utility process. Confirm plan-change rules with your distributor.
Disclaimer: Results are informational estimates for learning and planning only. Always follow the applicable electrical code and consult a qualified licensed electrician for safety-critical work.