Energy tariffs with free electricity hours (UK): compare & check if they’re worth it
Free-hour electricity tariffs can cut costs for some homes (especially EVs and storage heaters) but they often come with higher rates outside the free window. Use this guide to compare fairly and avoid common pitfalls.
- See how “free hours” work, who qualifies, and what to watch for
- Compare against a normal single-rate tariff using realistic UK examples
- Get a whole-of-market quote in minutes (no obligation)
Estimates only. Eligibility, rates, and free-hour windows vary by supplier, region, meter type, and payment method. Always check the tariff facts label before switching.
Fast answer: are free electricity hour tariffs worth it in the UK?
They can be worth it only if you can reliably shift a meaningful chunk of your electricity use into the free window (often overnight or at set off-peak times). In many cases, the standard (paid) unit rate is higher than on an ordinary tariff, so homes that can’t shift usage may pay more overall.
Key takeaways
- Best fit: EV charging at home, battery storage, storage heaters, or anyone who can schedule high-load appliances.
- Check the maths: compare standing charge, paid unit rate, and free-hour rules—not just the word “free”.
- Smart meter is usually required to measure the free window accurately (some tariffs are smart-meter-only).
- Exit fees and fixes can apply—especially with time-of-use or promo tariffs.
Quick “is it likely to suit me?” test
- Do you have (or can you get) a smart meter?
- If not, many free-hour tariffs won’t be available or may not bill correctly.
- Can you shift at least ~20–35% of your electricity into the free window?
- EV owners often can. Typical households without an EV often can’t.
- Are you willing to run appliances at specific times?
- If your routine is fixed (daytime use, electric cooking, tumble dryer at peak), it may not suit you.
How “free electricity hours” tariffs work
In the UK, these are usually a type of time-of-use electricity tariff. The supplier sets a window of hours where your unit rate is £0.00/kWh (or heavily discounted). Outside that window, you pay a (often higher) standard unit rate, plus a daily standing charge.
Common UK variations you’ll see
- Overnight free hours (often aimed at EV charging).
- Weekend free hours (good for laundry/dishwasher batching).
- Fixed free window vs dynamic time slots (some change by day or are app-controlled).
- Free hours capped (e.g., limited free kWh or “fair use” policy).
- Electricity-only deal where gas remains on a separate tariff.
What to check before you switch
- Free window times (and whether they change on weekends / bank holidays).
- Paid unit rate outside the window (this is where many people overpay).
- Standing charge (higher standing charge can wipe out free-hour gains).
- Eligibility rules: EV requirement, smart meter, app, direct debit, credit check.
- Exit fees and contract length (especially on fixes).
- Heat & hot water: if you rely on electric heating, ensure the free window aligns with comfort and control (timer/thermostat).
If you’re unsure, a safe approach is to compare total estimated annual cost using your real consumption and a realistic “shiftable” percentage.
Compare free-hour tariffs against the wider market
Free-hour deals aren’t automatically cheaper—so the key is a fair comparison using your meter type, payment method, and usage pattern. If you share a few details, we’ll help you see options that fit (including standard fixed/variable and other time-of-use tariffs where available).
What you’ll need
- Your postcode
- Whether you have a smart meter
- Rough annual usage (if known)
How to get a more accurate result
- Check your latest bill/statement
- Estimate what you can shift into the free hours
- Note any EV, battery, or electric heating
Get a whole-of-market quote
Compare tariff types: free hours vs single-rate vs Economy 7
Use this table to sanity-check a “free hours” offer. Your exact prices vary by region, payment method (direct debit vs prepay), and supplier—so treat this as a decision guide, not a quote.
| Tariff type | How it prices electricity | Typical requirements | Best for | Watch-outs |
|---|---|---|---|---|
| Free electricity hours | £0.00/kWh for set hours; higher paid rate outside; standing charge applies | Often smart meter + direct debit; sometimes app/EV-related eligibility | EV charging, battery storage, schedule-friendly households | Higher paid unit rate; free window rules/caps; exit fees on fixes |
| Single-rate (standard) | One unit rate any time; standing charge applies | Any meter type (including many prepay options) | Most households with typical usage patterns | Less opportunity to benefit from off-peak |
| Economy 7 / multi-rate | Cheaper night rate for ~7 hours; higher day rate; standing charge applies | Usually needs an Economy 7 capable meter; times vary by region | Homes with storage heating or consistent overnight load | If you don’t use enough at night, day rate can make bills higher |
Decision checklist: who it suits
- You can routinely run a high-load device in the free window (EV charger, immersion heater, washing machine, dishwasher, tumble dryer).
- You’re comfortable using timers/smart plugs or scheduling EV charging.
- You’ve checked the paid unit rate and it still looks competitive for your non-shiftable usage (cooking, lighting, daytime working from home).
- Your home has (or can get) a smart meter that’s communicating reliably.
Who it often doesn’t suit
- Your biggest electricity use is at peak times (electric cooking, electric showers, daytime heating) and you can’t shift it.
- You’re on prepayment and don’t want to change meter/payment method.
- You’re in a short-term rental and don’t want contract/exit fee risk.
- You prefer “set and forget” bills without timing rules.
Costs, exclusions and common pitfalls (UK-specific)
Most “surprises” come from the parts that aren’t free. Here’s what to check before you commit.
1) Higher paid unit rate
Many free-hour tariffs recover costs with a higher rate outside the window. If you only shift a little, the higher rate can outweigh the “free” benefit.
2) Standing charge differences
Standing charges vary by region and supplier. A higher standing charge particularly affects low-usage homes (e.g., small flats).
3) Eligibility & payment method
Some deals are limited to direct debit, credit meters, or smart-meter-only customers. If you’re on prepay, check whether a meter change is needed.
4) “Free” doesn’t always mean unlimited
Always look for fair-use policies, caps, or exclusions. Some suppliers may restrict unusually high consumption patterns.
5) Smart meter connectivity issues
If your smart meter isn’t communicating, billing can fall back to estimates or manual reads. Confirm how the supplier handles free windows if data is missing.
6) Contract length & exit fees
Fixed versions may include exit fees. If you’re likely to move or switch again soon, factor this into your decision.
Two realistic scenarios with numbers (worked examples)
These examples show how to compare. They are not quotes and do not reflect a specific supplier. Prices vary by region and change over time.
Scenario A: EV owner who can shift a lot (often works well)
- Annual electricity use: 4,200 kWh
- Shiftable into free hours: 35% (1,470 kWh) mainly EV charging
- Single-rate comparator: 28p/kWh, standing charge 55p/day
- Free-hours tariff assumption: 0p/kWh for the 35%; 36p/kWh for the remaining 65%; standing charge 55p/day
Estimated annual electricity cost:
- Single-rate: (4,200 × £0.28) + (365 × £0.55) = £1,176 + £200.75 = £1,376.75
- Free-hours: (2,730 × £0.36) + (365 × £0.55) = £982.80 + £200.75 = £1,183.55
In this setup, free hours help because a large chunk is genuinely shifted. If your paid rate were higher than 36p, the benefit could shrink or flip.
Scenario B: Typical flat with limited shifting (can cost more)
- Annual electricity use: 2,000 kWh
- Shiftable into free hours: 10% (200 kWh) dishwasher/laundry only
- Single-rate comparator: 28p/kWh, standing charge 55p/day
- Free-hours tariff assumption: 0p/kWh for 10%; 36p/kWh for 90%; standing charge 60p/day
Estimated annual electricity cost:
- Single-rate: (2,000 × £0.28) + (365 × £0.55) = £560 + £200.75 = £760.75
- Free-hours: (1,800 × £0.36) + (365 × £0.60) = £648 + £219 = £867.00
Here, the higher paid rate and standing charge outweigh the free portion. This is why shifting percentage is critical.
A simple way to estimate your break-even point
If we ignore standing charge differences for a moment, you can estimate the share you need in free hours:
(Paid rate on free-hours tariff - Unit rate on normal tariff) ÷ (Paid rate on free-hours tariff)
Example using 36p vs 28p: (36-28)/36 ˜ 22%. If you can’t shift around this share (and standing charge is similar), you may not benefit.
Remember: standing charges and your actual paid rate can change the result—always compare total estimated annual cost.
FAQs: free electricity hours tariffs in the UK
Do I need a smart meter for free-hour tariffs?
Usually, yes. Suppliers typically need half-hourly (or similar) readings to apply the free window correctly. If you don’t have a smart meter, you may be limited to standard tariffs or Economy 7-style options.
Are free hours available everywhere in the UK?
Availability can vary by supplier and by region (your electricity network area). Payment method and meter type also affect what you can access. The quickest check is a postcode-based comparison.
Does “free electricity” include the standing charge?
No. The standing charge is a daily fee that usually still applies, even during free-hour windows. Always compare standing charges as well as unit rates.
Can I get a free-hours tariff if I’m on prepayment?
Sometimes, but it depends on the supplier and your meter. Many free-hour tariffs are designed for credit meters paid by direct debit. If you’re on traditional prepay, you may need a meter change first—ask the supplier about eligibility and any checks.
What happens if I use electricity outside the free window?
You pay the tariff’s standard (paid) unit rate for that usage. That rate can be higher than a normal single-rate tariff, so it’s important to estimate how much you’ll realistically shift.
Can I run appliances automatically during free hours?
Often, yes—using appliance delay-start settings, smart plugs (where safe and suitable), immersion heater timers, or EV charger scheduling. Always follow manufacturer guidance and avoid unsafe setups (e.g., unattended high-heat appliances if not recommended).
Will my gas be free too if I’m on dual fuel?
Almost always no. “Free hours” are typically an electricity pricing feature. Your gas will have its own unit rate and standing charge (even if billed on the same account).
Is it hard to switch back if it doesn’t suit?
Switching is usually straightforward, but check whether your tariff is fixed with exit fees, and whether your meter setup (e.g., multi-rate) affects which tariffs you can move to next.
Trust, methodology and sources
Page details
- Written by
- EnergyPlus Editorial Team
- Reviewed by
- Energy Specialist
- Last updated
- February 2026
How we assess free-hour tariffs (and the limitations)
Our editorial approach is designed to help UK households avoid misleading “free” headline claims by focusing on total expected cost and eligibility constraints.
- Total annual cost: We compare estimated annual electricity cost using unit rates, standing charges, and an assumed share of usage in the free window.
- Eligibility checks: We highlight common requirements (smart meter, payment method, region/network, EV/battery conditions) because these often determine whether you can actually take the tariff.
- Behavioural reality: We factor in that many households can’t shift cooking/heating loads, so “free” time may not match real usage.
- What we don’t do here: We do not list live tariff prices on this page (they vary constantly by region and customer details). Use our comparison form for availability and current rates.
Sources (UK)
- Ofgem (UK energy regulator) – consumer guidance and market rules
- Citizens Advice: energy advice – switching, billing, and complaint routes
- GOV.UK: smart meters – overview of smart meter rollout and what to expect
Ready to compare free-hour tariffs with the rest of the market?
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