Energy tariffs with free electricity hours (UK guide)
Learn how “free hours” tariffs work in the UK, what you really pay outside the free window, and how to check if you’ll be better off—especially if you have an EV, heat pump, or can shift usage overnight.
- Plain-English explanation of free-hour tariffs vs EV time-of-use tariffs
- Eligibility checks: meter type, region, payment method and common exclusions
- Two realistic worked examples (with assumptions) + a comparison table
Figures are illustrative only. Free-hour windows, unit rates and standing charges vary by supplier, region and meter setup.
Fast answer: are free electricity hours tariffs worth it?
In the UK, “free electricity hours” tariffs (sometimes offered as free weekend hours or free overnight hours) can be worth considering if you can reliably move a meaningful chunk of your electricity use into the free window—think EV charging, washing/drying, dishwasher, or home battery charging.
However, many of these tariffs offset the free period with higher unit rates (and sometimes higher standing charges) at other times. The only way to know is to estimate your usage inside and outside the free hours.
Typically suits
- EV drivers who can charge mostly in the free window
- Households able to run appliances at set times
- Smart meter homes comfortable with time-based pricing
Often not ideal for
- High daytime electricity use you can’t shift
- People without a compatible meter set-up
- Those who prefer simple, fixed unit rates
Quick “sanity check”
If the tariff’s paid unit rate is noticeably higher than a standard tariff, you’ll usually need a large share of your kWh to be free (often EV-led) to come out ahead.
We show how to estimate this below.
How free electricity hours tariffs work (UK)
A free-hours tariff is a type of time-of-use electricity tariff where your unit rate is £0.00 per kWh during a defined window (for example, certain weekend hours). Outside that window, you pay a normal (often higher) unit rate, plus a daily standing charge.
What “free” usually means
- Unit rate
- £0.00/kWh for the stated hours only.
- Standing charge
- Still applies every day, even if you use no electricity.
- Other hours
- Usually priced higher than a basic single-rate tariff, depending on the deal.
Typical eligibility requirements
- Smart meter: many free-hours tariffs need half-hourly readings (or a compatible smart meter configuration).
- Direct Debit: some are only available on monthly Direct Debit (not prepayment).
- Region-specific pricing: unit rates and standing charges vary by electricity distribution region (postcode-driven).
- Online account/app: you may need to manage the tariff via an app or online portal.
Check what’s available for your postcode
We’ll compare whole-of-market home energy deals we can show you, including time-of-use options where available. Share a few details and we’ll help you shortlist tariffs that match your meter and usage.
A simple way to estimate if free hours will beat a standard tariff
You don’t need perfect data—just a reasonable split of your monthly kWh into:
- kWh during free hours (charged at £0.00/kWh)
- kWh outside free hours (charged at the tariff’s paid unit rate)
Step-by-step (quick)
- Find your typical monthly electricity use (kWh) from bills or your app.
- Estimate how many kWh you can move into the free window (EV + appliances).
- Calculate your paid kWh = total kWh - free-window kWh.
- Compare: (paid kWh × paid unit rate) + standing charge vs your current tariff.
What matters most
- Paid unit rate (outside free hours)
- Standing charge (daily, unavoidable)
- How “shiftable” your usage is (EV charging is the biggest lever)
- Free window timing (weekend vs overnight vs specific hours)
Common deal-breakers
- No smart meter / tariff not available for your meter type
- Free hours don’t align with your routine (or noise restrictions for appliances)
- Exit fees if you’re still in a fixed contract
Comparison: free hours vs EV off-peak vs standard tariff
Use this table to sense-check which tariff type matches your home. Always confirm exact hours, rates and eligibility with the supplier and your personalised quote.
| Tariff type | Best for | Typical pricing structure | Main risk | What to check |
|---|---|---|---|---|
| Free electricity hours | EV charging, weekend-heavy usage, battery charging | £0.00/kWh for set hours + higher paid rate other times + standing charge | Paid rate can outweigh the free hours if you don’t shift enough | Free window timing; standing charge; any caps/conditions; meter requirements |
| EV time-of-use (cheap overnight) | Regular overnight EV charging; people who can run appliances off-peak | Low off-peak unit rate (not free) + higher peak/day rate + standing charge | High peak rate if you use lots of electricity in the day | Off-peak hours length; peak/day rate; compatibility with your meter |
| Standard single-rate | Most households; predictable usage; minimal load shifting | One unit rate all day + standing charge | You miss out if you could shift a lot to off-peak/free windows | Exit fees; fixed vs variable; standing charge; customer service ratings |
Decision checklist (print this mentally)
This type of tariff may suit you if…
- You can shift at least a third of your electricity into the free window (often via EV charging or a battery).
- You’re happy scheduling appliances (and it won’t disturb sleep or neighbours).
- You have (or can get) a working smart meter providing readings reliably.
- You’ve checked any exit fees on your current fixed deal.
Consider alternatives if…
- Your biggest electricity loads are daytime (home working, electric cooking, medical equipment) and can’t move.
- You mainly heat your home with electricity and can’t time-shift it safely/comfortably.
- You’re on prepayment and the tariff is Direct Debit-only.
- You’d find variable time windows stressful or easy to forget.
Worked examples (illustrative UK scenarios)
These are simplified examples to help you think clearly about “free hours” pricing. They are not quotes. Rates, hours and standing charges vary by supplier and region.
Scenario A: EV driver who can use the free window
Assumptions: 400 kWh/month total electricity. You can schedule 220 kWh/month into the free hours (mostly EV charging). Remaining paid use: 180 kWh.
| Item | Free-hours tariff (example) | Standard tariff (example) |
|---|---|---|
| Paid unit rate | 38p/kWh (outside free hours) | 28p/kWh (all hours) |
| Standing charge | 55p/day | 50p/day |
| Monthly unit cost (est.) | 180 kWh × £0.38 = £68.40 | 400 kWh × £0.28 = £112.00 |
| Standing charge (est. 30 days) | 30 × £0.55 = £16.50 | 30 × £0.50 = £15.00 |
| Total monthly (est.) | £84.90 | £127.00 |
In this simplified example, the free-hours tariff wins because a large share of usage is genuinely shifted into the free window.
Scenario B: home-working household with limited flexibility
Assumptions: 300 kWh/month total electricity. You can only move 60 kWh/month into free hours (washing, dishwasher). Paid use: 240 kWh.
| Item | Free-hours tariff (example) | Standard tariff (example) |
|---|---|---|
| Paid unit rate | 38p/kWh (outside free hours) | 28p/kWh (all hours) |
| Standing charge | 55p/day | 50p/day |
| Monthly unit cost (est.) | 240 kWh × £0.38 = £91.20 | 300 kWh × £0.28 = £84.00 |
| Standing charge (est. 30 days) | 30 × £0.55 = £16.50 | 30 × £0.50 = £15.00 |
| Total monthly (est.) | £107.70 | £99.00 |
Here, the free-hours tariff loses because most usage remains on the higher paid rate.
Costs, exclusions and common pitfalls (UK)
Before switching, check the details that most often trip people up. We’ve set these out as quick “cards” so you can scan them.
1) Higher rates outside free hours
The paid unit rate can be significantly higher than standard tariffs. If you can’t shift enough kWh, your bill can rise even though some hours are free.
2) Standing charges still apply
“Free electricity” doesn’t mean “no bill”. Standing charges are still charged daily and vary by region.
3) Meter setup & readings
Time-of-use tariffs typically need a working smart meter and correct configuration. If your meter isn’t sending readings, billing can become messy.
4) Payment method restrictions
Some deals are Direct Debit-only and may not be offered to prepayment customers. Always check eligibility before you switch.
5) Exit fees on your current tariff
If you’re in a fixed deal, you could face an exit fee for switching early. Factor this into any estimated benefit.
6) Free window timing changes
Some suppliers can update tariff terms at renewal. If your routines depend on specific hours, confirm what happens at the end of the initial term.
FAQs: free electricity hours tariffs in the UK
Are free electricity hours tariffs really free?
They can be £0.00/kWh during the stated hours, but you still pay a standing charge, and you’ll pay a unit rate outside the free window. Always check the tariff information and your personalised quote.
Do I need a smart meter for free hours tariffs?
Often, yes. Many time-of-use tariffs require half-hourly readings from a smart meter (or a compatible setup). Without this, the supplier may not be able to bill you correctly for the free window.
Can I get a free-hours tariff on a prepayment meter?
It depends. Some tariffs are Direct Debit-only and not available on prepayment. If you’re on prepay, check eligibility carefully before assuming you can switch to a specific time-of-use product.
Will my whole home get free electricity during the free hours?
Typically yes—the free unit rate applies to all electricity usage recorded by the meter during that window, not just EV charging. But terms vary, so confirm whether there are any restrictions or fair use clauses.
What if I have solar panels or a home battery?
Solar and batteries can change the maths. If you can charge a battery during free hours and use it later, you may increase the benefit—but check battery round-trip efficiency and any export tariff terms. If you export to the grid, consider how an import tariff interacts with your export arrangement.
Do free hours tariffs exist for gas too?
Free-hour promotions are mainly seen on electricity. Gas is usually single-rate. If your home uses a lot of electricity for heating (e.g., heat pump), focus on how much of that heating load can realistically be shifted without impacting comfort.
Can my supplier change my tariff hours or prices?
If you’re on a fixed-term tariff, the unit rates and structure are typically fixed for that term, but always read the contract details. At renewal, suppliers can offer new terms, so re-check the free window and rates before you accept.
Is switching risky—will my supply be interrupted?
Switching energy supplier in Great Britain should not interrupt your supply. Your gas and electricity still come through the same pipes and wires; only the billing and tariff change. If anything goes wrong, consumer protections apply—check Ofgem guidance for the current process.
Trust, methodology and sources
Page ownership
- Written by: EnergyPlus Editorial Team
- Reviewed by: Energy Specialist
- Last updated: March 2026
How we assess free-hours tariffs (our approach)
We focus on what changes your bill in real life: paid unit rates, standing charges, free window timing and how much usage can realistically be shifted. For the worked examples above, we used:
- Monthly electricity usage (kWh) split into “free-window” and “paid” usage.
- Illustrative unit rates and standing charges to demonstrate the mechanics.
- A simple monthly cost view: (paid kWh × paid unit rate) + (days × standing charge).
This guide does not attempt to list every supplier’s current free-hours offer (availability changes frequently and is postcode-dependent). Instead, we show you how to evaluate any offer you find.
Independent UK sources we reference
- Ofgem (UK energy regulator) — consumer guidance, switching and smart metering information
- Citizens Advice: energy — practical help on bills, tariffs and complaints
- GOV.UK: switch your energy supplier — overview of switching process and what to expect
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