Energy tariffs with free electricity Sundays (UK guide)
Looking at “free electricity on Sundays” deals? This UK guide explains how they work, what’s really free, who they suit, and how to compare them safely before you switch.
- Understand the typical terms: time windows, caps, and eligibility
- See worked examples (with assumptions) to estimate whether you’d save
- Compare against standard, fixed and time-of-use tariffs with a simple checklist
Estimates only. Availability and terms vary by supplier, region, meter type and payment method. Always check the tariff facts/terms and your annual cost.
Fast answer: are “free electricity Sundays” tariffs worth it?
They can be worth it if you can reliably shift a chunk of your electricity use into the “free” Sunday window (for example, washing, drying, dishwasher, batch cooking, EV charging where permitted) without paying a higher rate the rest of the week that cancels out the benefit.
Key takeaways
- “Free” usually means electricity unit charges are reduced in a set Sunday time window (terms vary). Standing charges still apply.
- Eligibility may depend on your meter (smart meter often required), region, and whether the tariff is available to new or existing customers.
- Best for households with flexible usage (laundry, dishwashing, cooking, EV charging where allowed) and the discipline to shift it.
- Not automatically cheaper: some deals may have higher unit rates at other times or different standing charges.
What to check before you switch
- What hours count as “free” (and whether it’s every Sunday, selected Sundays, or seasonal)
- Any caps/fair use wording, or limits on which consumption qualifies
- Whether your tariff is fixed or variable, and any exit fees
- How it works with economy/time-of-use meters and prepayment (often restricted)
Quick rule of thumb: if you can’t shift at least 10–20% of your electricity usage into the free Sunday window, these deals are less likely to beat a strong fixed tariff — but you should still compare your estimated annual cost on your actual usage.
How “free electricity Sundays” tariffs work in the UK
In the UK, these are usually promotional time-of-use tariffs. Instead of a single unit rate all week, the supplier applies a special Sunday rate (sometimes shown as 0p/kWh for a set window) and a different rate at other times.
What’s typically included (and what isn’t)
- Electricity unit price in the Sunday window
- May be free/discounted for a defined time (e.g., daytime hours). Outside that window, normal rates apply.
- Standing charge
- Still applies daily. “Free” does not normally remove the standing charge.
- Gas prices
- Often unaffected. If you’re dual fuel, you still need to compare the gas unit rate and standing charge too.
- Smart meter / meter settings
- Many time-of-use tariffs require a smart meter so your usage can be recorded by time period.
Important: the exact Sunday hours and whether the rate is truly 0p/kWh varies by supplier and product. Always check the tariff information and your supplier’s terms before switching.
Who it suits (and who it doesn’t)
Often suits
- Households at home on Sundays
- People who can batch laundry/dishwasher runs
- EV owners who can charge on Sundays (where the tariff allows EV charging)
- Homes with high electricity use (so the “free” chunk is meaningful)
Often not ideal
- People out most Sundays
- Low electricity users (small flats, low occupancy)
- Anyone who can’t shift usage due to routines or care needs
- Customers who need predictable bills and prefer simple single-rate tariffs
Tenants: you can usually switch supplier if you pay the bills, but check your tenancy agreement and ensure you can access the meter (especially for smart meter appointments).
Compare Sunday deals properly (and get a quote)
The safest way to judge a “free Sundays” tariff is to compare estimated annual cost using your own consumption and meter setup. If you don’t have exact Sunday usage, you can still compare by estimating how much you can realistically shift.
Before you use a “free Sundays” tariff, ask yourself:
- How many kWh could you shift to the Sunday window? (Laundry, dishwasher, cooking, immersion heater, EV charging if applicable.)
- What is the unit rate outside Sunday, and is it higher than your current tariff?
- Are there any restrictions: smart meter requirement, region availability, prepayment limits, EV exclusions, or fair use?
- Is it fixed or variable — and are there exit fees?
Tip: if you have a smart meter and online account/app, look for half-hourly/day-by-day usage to estimate what you already use on Sundays. That gives you a more reliable comparison than guessing.
Get a whole-of-market quote
Tell us a few details and we’ll show available tariffs, including any time-of-use offers, so you can compare based on your home and meter.
Two realistic scenarios (with numbers)
Scenario A: family home, can shift laundry + cooking
Assumptions (example): 3,600 kWh/year electricity. Current single-rate 26p/kWh, standing charge not compared here for simplicity (assumed similar). "Free Sunday" window covers 8 hours weekly at 0p/kWh; all other usage at 30p/kWh. Household can shift 8 kWh each Sunday into the free window (dishwasher, 2x washing cycles, batch cooking).
- Shifted to free: 8 kWh/week × 52 = 416 kWh/year
- Cost on current tariff for those units: 416 × £0.26 = £108.16
- On “free Sundays” tariff: 416 × £0.00 = £0 (units only)
- But rest of usage costs more: (3,600 - 416) = 3,184 kWh; extra 4p/kWh vs current = 3,184 × £0.04 = £127.36 more
Estimated net: £108.16 “saved” on Sundays - £127.36 extra elsewhere ˜ £19.20 worse off (before standing charges/any caps).
Scenario B: EV driver, shifts charging to Sunday
Assumptions (example): 5,000 kWh/year electricity (includes EV). Current single-rate 26p/kWh. “Free Sunday” tariff: 0p/kWh for Sunday window; 28p/kWh otherwise. Driver can charge 25 kWh every Sunday within the free window (where permitted by tariff terms).
- Shifted to free: 25 kWh/week × 52 = 1,300 kWh/year
- Cost on current tariff for those units: 1,300 × £0.26 = £338.00
- On “free Sundays” tariff: 1,300 × £0.00 = £0 (units only)
- Other usage costs +2p/kWh: (5,000 - 1,300) = 3,700 kWh; extra = 3,700 × £0.02 = £74.00 more
Estimated net: £338.00 “saved” - £74.00 extra ˜ £264.00 better off (before standing charges/any caps).
If your tariff includes a cap, fair use clause, or excludes EV charging from the free period, the outcome may be different. Always check terms.
These scenarios are illustrative and use example rates. Your actual rates depend on supplier, region, meter type and payment method. Standing charges, VAT and tariff rules can materially change the result.
Compare your options: Sunday-free vs other tariff types
| Option | What you get | Best for | Watch-outs |
|---|---|---|---|
| “Free Sundays” electricity | Discounted/0p unit rate during a defined Sunday window | Flexible households; high users; some EV drivers | Higher rates other days; smart meter requirements; caps/fair use; standing charges still apply |
| Standard variable tariff (SVT) | Default tariff; price can change (often tracks Ofgem cap level) | People who want flexibility and no exit fees | Not always the cheapest; rates can rise; no “perks” |
| Fixed tariff | Unit rate/standing charge fixed for a set term | Budget certainty; households that can’t shift usage | Exit fees; may miss out if prices fall; check end date |
| Time-of-use (e.g., day/night or half-hourly) | Cheaper periods at set times; more granular pricing | EV owners, storage heating, highly flexible households | Complex; smart meter usually required; peaks can be expensive |
Decision checklist
- I can shift a consistent amount of electricity into the Sunday window (not just once or twice).
- I’ve compared annual cost using my usage (kWh) or a realistic estimate.
- I know my meter type (smart meter / traditional / Economy 7) and the tariff is compatible.
- I’ve checked exit fees and whether the tariff is fixed or variable.
- I’ve read the key terms: Sunday hours, what qualifies as “free”, and any fair use/caps.
Good Sunday shift ideas (typical)
- Dishwasher cycle(s)
- Washing machine + tumble dryer (where needed)
- Batch cooking / slow cooker
- Immersion heater boosts (if suitable)
- EV charging (only if allowed and within the time window)
Always use appliances safely and follow manufacturer guidance. Avoid overloading extension leads and consider off-peak noise for neighbours in flats.
Costs, exclusions and common pitfalls (UK-specific)
1) Higher rates the rest of the week
Some “perk” tariffs recoup the cost with higher unit rates outside the free window. Always compare the full week, not just Sunday.
2) Standing charges still apply
“Free electricity” typically does not mean “no daily charge”. Standing charges can be a big part of annual cost, especially for low users.
3) Smart meter and half-hourly reads
Time-of-use tariffs often require smart metering so usage can be assigned to the Sunday window. If you can’t get a smart meter installed, availability may be limited.
4) Payment method restrictions
Some deals may be limited to Direct Debit and may not be available for prepayment meters. Always check eligibility.
5) “Fair use”, caps and exclusions
Some suppliers include fair use wording or limits on what counts as free/discounted usage. If you’re relying on EV charging or heavy loads, read the terms carefully.
6) Exit fees and end dates
If it’s a fixed term, there may be exit fees. Promotional perks can also change at renewal, so set a reminder to review before the end date.
Reality check: if you end up running extra appliances just because the electricity is “free”, you might use more energy overall. The best outcome usually comes from shifting usage, not increasing it.
FAQs
Is electricity really free on Sundays?
Usually it means the unit rate for electricity is reduced (sometimes to 0p/kWh) during a defined Sunday time window. You’ll typically still pay a standing charge, and usage outside the window is charged at normal rates.
Do I need a smart meter for a “free Sundays” tariff?
Often, yes. Time-of-use pricing usually needs a smart meter (or another compatible meter setup) so your supplier can measure usage in the Sunday window accurately. Availability varies by supplier and tariff.
Can I get a free Sundays tariff with an Economy 7 meter?
Sometimes, but not always. Economy 7 already has separate day/night rates. Some suppliers may require a smart meter and move you to a different time-of-use setup. Check compatibility and whether your heating/hot water relies on Economy 7 timings.
Will a free Sundays tariff lower my whole bill?
Not automatically. Your total bill depends on your standing charge, your unit rate outside Sunday, and how much usage you can genuinely shift into the free window. Always compare estimated annual cost based on your consumption.
Are these tariffs available in every UK region?
No. UK energy pricing and product availability can vary by region. Some tariffs are also limited to certain customer groups (new customers only, specific meter types, Direct Debit). Use your postcode to check what’s available.
What about prepayment meters?
Many specialist time-of-use or promotional tariffs are limited to credit meters and Direct Debit, though policies vary. If you’re on prepay, focus on tariffs that explicitly support your meter type and compare the total annual cost.
Can I switch if I’m renting?
In many cases, yes — if you’re responsible for paying the energy bill. You may need your landlord’s permission for certain changes (for example, a smart meter installation) and you should be able to access the meter. If unsure, check your tenancy agreement or ask your landlord/agent.
Are there exit fees?
Sometimes. Fixed tariffs often include exit fees, while standard variable tariffs usually don’t. If a Sunday-free tariff is fixed-term, check the tariff information for exit fees and how renewal works.
How can I estimate my Sunday usage?
If you have a smart meter and supplier app/online account, look for half-hourly or daily charts for recent Sundays. If you don’t, you can estimate by adding typical appliance use (kWh) for what you’d run during the window — but treat the result as a rough guide.
Trust, methodology and sources
Page governance
- Written by: EnergyPlus Editorial Team
- Reviewed by: Energy Specialist
- Last updated: March 2026
We review key sections when supplier products change, Ofgem updates guidance, or common user questions shift.
How we assess “free Sundays” tariffs
Our comparisons focus on whether a tariff is likely to reduce total annual cost for a given household — not whether the perk sounds attractive.
- Inputs we consider: region (postcode), meter type (smart/Economy 7/standard), payment method (Direct Debit/prepay), electricity usage (kWh), and any ability to shift load to Sundays.
- What we compare: estimated annual unit costs across all periods + standing charges (where available), plus contract terms (fixed/variable), exit fees and eligibility.
- Limitations: “free” windows, caps/fair use, and eligibility vary by supplier and can change. If you don’t have half-hourly usage data, Sunday shifting is an estimate.
- What we don’t do: we don’t promise savings. We encourage users to verify tariff terms and use their real consumption where possible.
Why terms matter: two “free Sundays” deals can look similar but differ on Sunday hours, what’s included, and the weekday unit rate — which often decides whether you’re better off overall.
Ready to see if a free Sundays tariff works for your home?
Compare available UK tariffs by postcode and meter type. We’ll help you focus on total annual cost, not just the perk.
Reminder: switching is usually straightforward, but always confirm the tariff’s Sunday hours, eligibility, and any exit fees before you commit.
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