Best UK energy tariffs with free electricity hours (what to check)
Free-hour tariffs can work well if you can shift usage (like EV charging, laundry or dishwashing) into the supplier’s set free window. This guide explains how they work in the UK, what eligibility and meter setup you need, and how to compare them safely.
- Understand what “free” really means (and what it can cost elsewhere)
- See realistic examples with numbers and clear assumptions
- Compare options by meter type, household habits and risk level
Figures are illustrative and depend on your region, meter type, payment method and tariff terms. Always check the supplier’s tariff information label before switching.
Fast answer: are free electricity hours worth it?
They can be—but only if you can reliably move a meaningful chunk of your electricity use into the free window and you understand what you may pay outside it. In the UK, these tariffs are typically time-based deals (often aimed at EV drivers) where certain hours cost £0/kWh (or close to it), while other hours may be higher than standard tariffs.
Best for
- EV charging at home on a schedule
- Flexible households (laundry/dishwasher overnight)
- Homes with batteries that can charge in the free window
Watch out for
- Higher day rates / peak rates
- Smart meter and data requirements
- Standing charges and regional price differences
Quick rule of thumb
If you can shift roughly 25–40% of your electricity into the free/cheap hours (or most of your EV charging), these tariffs are more likely to compete. If your usage is mostly daytime and can’t move, a standard tariff may be simpler and safer.
Important: “Free electricity hours” usually apply to unit rates only. You still pay the daily standing charge, and gas (if you have it) is priced separately. Terms vary by supplier and can change.
How free-hour energy tariffs work in the UK
In most cases, “free hours” are a type of time-of-use electricity tariff. The supplier sets a window where the electricity unit rate is £0/kWh (or very low). Outside that window, the unit rate can be higher to compensate. You’ll normally see one of these patterns:
- 1) Fixed free window (same hours each day)
- Example: a set block overnight or a set block on Sundays. Good for predictable routines.
- 2) EV-linked or smart charging window
- Some deals work best when you use a compatible EV charger/app and allow managed charging.
- 3) Dynamic or tracker-style variants
- Rates can vary more often. These aren’t always “free hours”, but may include ultra-low periods. They require higher attention and can be riskier.
What you typically need (eligibility basics)
- Smart meter (usually SMETS2) capable of half-hourly readings
- Agreement to share half-hourly consumption data (often required for time-of-use billing)
- Correct meter configuration (single-rate smart meter is common; legacy Economy 7 can complicate some switches)
- UK domestic supply (these tariffs are for households, not business meters)
Renters: you can usually switch supplier if you pay the energy bills, but check your tenancy agreement and whether the meter is accessible. If you’re on a prepayment meter, “free hour” availability can be limited.
Compare whole-of-market options
Tell us a few details and we’ll show suitable tariffs, including time-of-use and any free-hour options we can match to your meter type and postcode.
Tip before you compare: Look at a recent bill or your in-app usage. Free hours are most valuable when you can schedule high-consumption appliances (EV, tumble dryer, immersion heater, heat pump top-ups) inside the window.
Two realistic scenarios (with numbers)
Below are illustrative examples to show the trade-off. Your rates depend on region, supplier, and the tariff’s exact hours. We include standing charge to keep it realistic.
Scenario A: EV driver who can shift load
- Home uses 3,600 kWh/year electricity (typical medium-ish usage)
- EV adds 2,000 kWh/year charged mostly during the free window
- 40% of total electricity lands in free hours (2,240 kWh/year)
- Standing charge assumed 55p/day (regional variation applies)
Free-hour tariff (illustrative): 0p/kWh in window; 32p/kWh outside
Estimated annual cost: (3,360 kWh × 32p) + (365 × 55p) ˜ £1,276
Standard single-rate comparison: 24p/kWh, same standing charge ? (5,600 kWh × 24p) + standing ˜ £1,546
Illustration suggests free-hour can win when a big chunk (like EV) is reliably shifted. Rates used are examples only.
Scenario B: Daytime household with limited flexibility
- Home uses 3,100 kWh/year electricity
- No EV; most usage is cooking, home working, kids bedtime
- 12% lands in free hours (372 kWh/year)
- Standing charge assumed 55p/day
Free-hour tariff (illustrative): 0p/kWh in window; 32p/kWh outside
Estimated annual cost: (2,728 kWh × 32p) + standing ˜ £1,074
Standard single-rate comparison: 24p/kWh ? (3,100 kWh × 24p) + standing ˜ £949
Illustration shows the common pitfall: free hours don’t help much if most usage is outside the window and the peak rate is higher.
Reality check: Actual tariffs can include multiple unit rates (peak/off-peak), eligibility requirements (e.g., EV ownership, smart charging app), and different standing charges by region. Use these scenarios as a framework, not a promise.
Compare free-hour tariffs: what matters most
When you compare, ignore the headline “free” first and work through the deal structure. This table shows the most common features and the questions that change the answer.
| Feature | Why it matters | What to check before you switch | Who it suits |
|---|---|---|---|
| Free window timing | If the hours don’t match your routine, the benefit disappears. | Exact days/times; does it change seasonally; is it UK time/BST aware. | People who can schedule appliances reliably. |
| Unit rate outside free hours | A high peak rate can outweigh the free hours. | Peak/day rate (and any shoulder rate); compare to your current unit rate. | Homes with high shiftable load (EV/battery/immersion). |
| Standing charge | You pay this every day regardless of usage. | Your region’s standing charge; electricity-only vs dual fuel differences. | Lower usage homes should be extra careful. |
| Meter and data requirements | Some tariffs need half-hourly data to bill correctly. | Smart meter type (SMETS2); consent for half-hourly reads; compatibility for multi-rate. | Homes already on smart meters. |
| Exit fees & contract length | You may pay to leave early if the tariff doesn’t suit. | Exit fee per fuel; whether it’s fixed-term; price change clauses on variable tariffs. | Confident switchers who’ve modelled usage. |
| Payment method | Direct Debit deals can differ from prepayment/receipt of benefits. | Direct Debit vs prepayment availability; any fees; billing frequency and app usage. | Direct Debit households typically see wider choice. |
Decision checklist (quick and practical)
- Do I have a smart meter (or can I get one) and am I happy with half-hourly reads?
- Can I shift at least 25% of my electricity into the free/cheap window?
- What are my top 3 high-usage loads (EV, tumble dryer, immersion, electric heating)?
- Is the peak rate higher than my current tariff—and by how much?
- Am I locking into exit fees?
- Will the free window still work in school holidays, winter routines, and if someone works from home?
Who it suits (and who it doesn’t)
Likely to suit
- EV owners with off-peak charging
- Battery storage owners
- Households comfortable using timers/schedules
Often not worth it
- Low usage homes with high standing charges
- Mostly daytime usage (home working + cooking)
- Households that can’t reliably use the free window
If you’re unsure, compare using your actual half-hourly usage (if available) or a bill-based estimate, rather than assuming you’ll change your habits later.
Costs, exclusions and common pitfalls
Free-hour tariffs can be excellent in the right home, but the details matter. These are the most common reasons people feel disappointed after switching.
1) “Free” doesn’t include standing charge
You’ll still pay the daily standing charge. For low-use homes, this can be a big part of the bill regardless of free hours.
2) Peak rates may be higher
Some tariffs recover the “free” cost with higher unit rates at other times. If you can’t shift usage, you may pay more overall.
3) Smart meter and half-hourly data
Without the right smart meter setup (and permission for half-hourly reads), you might not be eligible or may be billed incorrectly.
Other exclusions to look for
- EV requirement (some deals expect EV ownership or smart charging integration)
- Prepayment limitations (choice can be narrower)
- Economy 7 / multi-rate meters (may require reconfiguration or may not be supported)
- Export/solar/battery conditions (if you have solar PV, check how export is handled)
Practical ways to avoid bill shocks
- Take a meter reading (or screenshot smart meter app usage) before you switch.
- Set timers for high-load appliances inside the free window.
- For EVs: confirm the car/charger schedule actually starts in the free window (and accounts for BST changes).
- Re-check bills for the first 1–2 months to ensure the time bands are applied correctly.
If something looks wrong: contact the supplier first, then use the supplier’s complaints process. In the UK, unresolved complaints can be escalated to the Energy Ombudsman after the supplier’s process/time limits.
FAQs: free electricity hours tariffs (UK)
Are “free electricity hours” really free?
Usually the electricity unit rate is free during set hours, but you still pay the standing charge. Outside the free window, the unit rate can be higher than standard tariffs. Always check the tariff information label and unit rates for each time band.
Do I need a smart meter?
In most cases, yes. Time-of-use billing typically requires a smart meter and permission for half-hourly readings. If you don’t have one, some suppliers may install it, but availability and timelines vary.
Can I get a free-hour tariff on Economy 7?
Sometimes, but it depends on the supplier and how your meter is configured. Some free-hour deals assume a single smart meter with half-hourly settlement. If you’re on Economy 7 (multi-rate), you may need a meter exchange or reconfiguration.
What if I’m on a prepayment meter?
Choice can be more limited and not all time-of-use/free-hour tariffs are available on prepayment. If you can move to credit meter/Direct Debit, you may see more options—but check fees, eligibility and whether it’s right for your budgeting.
Do free hours apply to gas too?
Usually not. These tariffs are typically about electricity time bands. If you have dual fuel, your gas price will have its own unit rate and standing charge.
Will I always save money if I charge my EV in the free window?
Not always. EV charging is a strong match, but overall cost depends on how much electricity you use outside the free hours, your standing charge, and the tariff’s non-free unit rates. It’s possible for EV drivers to pay more if the peak rate is significantly higher and household usage is mostly peak-time.
What happens when the clocks change (BST/GMT)?
Tariff hours should be defined clearly by the supplier. Some time-of-use systems adjust automatically; others may reference GMT or local time. If you rely on timers (EV charger, appliances), double-check around clock changes to avoid charging in the paid window.
Is switching risky? What protection do I have?
Switching is regulated in the UK. You should receive clear tariff details (including prices and any exit fees). If you have problems with billing or switching, you can complain to the supplier and escalate to the Energy Ombudsman if unresolved. For general rights and support, see Citizens Advice energy guidance.
Trust, methodology and sources
Page ownership
- Written by: EnergyPlus Editorial Team
- Reviewed by: Energy Specialist
- Last updated: March 2026
We aim to keep this guide current, but tariff availability and eligibility can change quickly. Always verify the latest prices and terms with the supplier before you switch.
How we assess “best” free-hour tariffs
Because free-hour tariffs differ by region and personal usage patterns, we don’t name a single universal “best”. Instead, we assess suitability using:
- Total estimated annual cost using standing charge + time-banded unit rates (not just the free rate)
- Eligibility friction (smart meter needs, half-hourly data consent, EV/charger requirements)
- Risk and complexity (number of rate bands, potential bill volatility, behaviour change required)
- Exit fees and contract terms (fixed/variable, penalties for leaving)
- Transparency (clarity of time windows, billing rules around clock changes)
Limitations: our scenarios use illustrative rates to demonstrate trade-offs. Your actual quote depends on your postcode, meter type, payment method, and current market pricing.
Sources and UK guidance
- Ofgem (UK energy regulator) – rules, consumer protections and market information
- Citizens Advice: energy – help with bills, switching, complaints and practical support
- GOV.UK: switching energy supplier – overview of the switching process
- Energy Ombudsman – dispute resolution if a complaint can’t be resolved
Ready to see if free-hour tariffs suit your home?
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EnergyPlus is a whole-of-market comparison service for UK homes. Prices and eligibility vary by supplier, region, meter type and payment method.
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