Start with the live cards above. Open Full plan details for the relevant allowance, minimum term and last-verified offer information, then use View Deal for the actual tariff. If six selected offers do not include the amount of data you need, explore our full giffgaff SIM listings and Lebara SIM listings. The rest of this comparison explains which option may suit your actual usage, payment period and coverage.
Coverage first: O2 or Vodafone at the places that matter?
This is a comparison between two different underlying networks. giffgaff uses O2, while Lebara uses Vodafone. A cheap plan on either network is poor value if you cannot reliably make calls or use data where you spend most of your time.
Check home, work, your commute and the indoor rooms where you lose signal. Ofcom's Map Your Mobile shows independent coverage predictions, not a promise for your exact room or handset. If coverage is close, test the network on a flexible SIM before moving the phone number you depend on. You can also compare other providers on O2's network or Vodafone's network without assuming those brands offer identical speeds or features.
A change in the broader Vodafone–Three network does not mean every Lebara customer automatically gains every Three mast or a Vodafone-branded premium feature. In the same way, the O2 network behind giffgaff does not guarantee identical service to every O2-branded tariff. Real performance depends on network agreements, local demand, compatible bands and the actual device. Our MVNO coverage and speeds guide explains the distinction.
What about 5G speeds? Both sell access to 5G where the relevant plan and handset support it. That does not establish a national winner for average download speeds or crowded places; a generic O2-versus-Vodafone speed result is not a controlled test of these two SIMs. Choose by local experience and the services you need, not a fabricated speed ranking.
The hidden cost difference: a calendar month is not 30 days
One of the most useful distinctions is how the regular flexible products are renewed. giffgaff's standard rolling plan lasts one calendar month; Lebara's standard rolling plan lasts 30 days. An advertised charge “per month” and one “per 30 days” are not necessarily directly comparable, even when the data allowance matches.
For an uninterrupted 365-day period, a succession of giffgaff calendar-month plans normally involves 12 payments, while a succession of Lebara 30-day plans normally requires 13 paid periods: twelve times 30 days is only 360 days. The thirteenth 30-day period extends beyond the 365-day window. Start dates, discounts, billing arrangements and other product types can change the comparison.
Here is a fictional illustration, not an actual giffgaff or Lebara price comparison. Assume identical usable UK data, equivalent service and no extras or discounts:
| Fictional service | Advertised charge | Payments for 365 continuous days | Total paid |
|---|
| Plan A: calendar-month rolling | £10 per calendar month | 12 | £120 |
|---|
| Plan B: 30-day rolling | £9 per 30-day period | 13 | £117 |
|---|
Plan B is £3 cheaper over this period. But if Plan B instead costs the same £10 per 30 days, the result becomes £130 against £120, even though both headline charges say £10. Neither calculation determines the cheaper real brand: you must substitute the current plans you qualify for and allow for promotional renewals, the data you actually use and any extra charges.
Do the longer contracts change the calculation?
Yes, substantially. giffgaff offers an 18-month mobile contract range, which can have different data allowances and pricing from its rolling products. Lebara separately offers 12-month SIM-only plans. A contract may lower the regular charge, but it is not a cancel-anytime rolling package. Compare the total minimum commitment, rather than putting a discounted 18-month rate beside a flexible 30-day tariff as though they were equally easy to leave.
If you leave giffgaff's 18-month contract early, its published calculation uses 50% of the current or most recent plan charge multiplied by the full months remaining. For instance, with a purely illustrative £12 plan and six full months remaining, that produces a £36 early-exit charge, in addition to charges otherwise due. You can switch between eligible data levels within the same contract product without restarting the 18-month term, but you cannot assume every plan type is interchangeable. Changing the allowance is not the same as ending the commitment.
Lebara's 12-month plans are a different commitment from its flexible 30-day products. If you leave before the minimum term ends, check the early-termination calculation in the terms for the exact plan you buy and the service end date. Do not assume the rolling-plan cancellation rules apply to a 12-month product, or that a 12-month agreement always means twelve consecutive 30-day payments. A discounted charge is no saving if you must keep paying after you no longer need the SIM.
The practical comparison is: same real dates, enough data, number of payments, price after any promotion, then possible exit charges. Our no-contract SIM deals are relevant if flexibility matters more than a long-term discount.
Calling overseas from the UK: where Lebara can change the total
A UK voice allowance does not necessarily cover calls to a number abroad. With giffgaff, ordinary international calls from the UK fall outside the included UK minutes and use credit at destination-specific rates. Lebara includes selected international minutes with its SIM-only plans, with the number of minutes and eligible destinations varying by product.
This matters when you regularly call overseas landlines or mobile numbers, not just when you browse a web page about international calling. A Lebara plan can be better value even if its domestic data allowance costs a little more — but only when your exact destination, number type and calling volume are covered. An “international minutes” label does not promise free calls to every overseas number or that unlimited UK data means unlimited calls abroad.
Test the value of included minutes, not the advertising label
Imagine two fictional SIMs with identical usable UK data and equally good coverage: Option A costs £7 per payment period, plus 15p for every international minute; Option B costs £9 and includes all the example calls. These figures are invented, not either operator's rates. In a like-for-like payment period:
| Overseas calling per period | Option A | Option B | Lower cost |
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| 5 minutes | £7.75 | £9 | A |
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| 15 minutes | £9.25 | £9 | B |
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| 30 minutes | £11.50 | £9 | B |
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The switch in value comes from useful eligible minutes, not from a permanent brand winner. For an actual purchase, match the same coverage dates, check the correct overseas landline or mobile rate and confirm that your Lebara plan includes the destination. Internet calls over WhatsApp or FaceTime normally use Wi-Fi or mobile data instead of the mobile network's international voice-minute allowance.
Use our guide to SIMs for international calls from the UK for destination-specific considerations. You can also explore Lebara's international-calling plans using the verified partner link, then return to our tracked Lebara offers to see each tariff's View Deal. The overseas-calling page does not replace checking your exact bundle.
EU roaming: does 5GB versus 30GB actually matter to you?
giffgaff's published rules allow up to 5GB of included data per plan in eligible EU and selected destinations, or less if your UK data allowance is smaller. Beyond the included cap, data may be charged from credit; a travel data add-on, credit spend cap or eligible early plan renewal may help avoid surprises. The 5GB is per qualifying plan, not a fresh allowance for every country or calendar month of a trip.
Joining giffgaff shortly before travelling? Included EU roaming is subject to UK-residency and usage checks. Its guidance says new members without prior UK usage may not qualify immediately; they may need to confirm UK residence with support. Its included roaming is also intended for temporary trips, with a 63-day eligibility rule for qualifying UK users. Check roaming status in your account before relying on it abroad — even when the plan advertises 5GB.
Lebara's eligible SIM-only plans allow up to 30GB of roaming data in the listed European destinations and other specified places, including India and Ukraine. A plan with only 5GB of UK data still has at most 5GB available as part of its allowance abroad. A higher roaming ceiling does not mean unlimited data, worldwide roaming or an exception to fair-use restrictions. Lebara's rules are designed for customers who live mainly in the UK and make temporary trips; prolonged overseas use can trigger surcharges.
For a traveller who expects 12GB in Spain on a single eligible plan, a qualifying Lebara bundle with at least that much included roaming data is a natural first check. A giffgaff plan with ample UK data still has a 5GB standard roaming ceiling, so the traveller must assess add-ons or other costs for the remaining data. For a weekend using 1GB, both may be sufficient and the network at home may matter much more. Compare the destination and your actual expected usage rather than assuming the bigger cap always wins.
India is not the same as “EU roaming”. Lebara explicitly includes India in its Roam Like Home destination scheme, whereas you must separately check giffgaff's India rates and options. Ukraine also appears on Lebara's published included-destination list, but service availability and fair-use conditions still apply. Other European countries can be excluded from standard zones. Our EU roaming SIM comparison helps if travel is your main purchase reason.
One specific trap: if you plan to use a newly activated Lebara eSIM abroad, Lebara's published help says that Roam Like Home data is blocked for the first seven days after activation while roaming in the EU or India. Activate the eSIM in the UK before departure. If you need data during that seven-day window, Lebara says a separate roaming add-on may be required. Do not order a new eSIM immediately before flying and assume included roaming data will work on arrival.
eSIM, Wi-Fi Calling and the everyday experience
Which is easier to activate as an eSIM?
giffgaff currently provides app-based eSIM activation for both new and existing customers with compatible, unlocked phones. A customer moving from physical SIM to eSIM must follow its replacement process, and the old SIM stops working after a successful switch. giffgaff's eSIM setup depends on its app; it does not offer the same generic manual QR-code path as every other provider.
Lebara's eSIM launch is more limited for new customers. Its current official onboarding instructions specify an Apple iPhone Air for new eSIM orders, while existing customers have a separate migration procedure. This can be decisive if your phone supports eSIM in general but is not eligible for Lebara's new-customer process. Do not assume that an eSIM-compatible phone, a travel-data eSIM and a UK voice-number SIM are interchangeable. Our UK mobile networks supporting eSIM guide covers the wider market.
What about 4G Calling and Wi-Fi Calling?
Both providers support VoLTE/4G Calling and Wi-Fi Calling with compatible devices and account configurations. The old comparison tables found elsewhere online can be misleading when they still mark these as unavailable. However, a handset working with Wi-Fi Calling on one provider may need a different supported configuration on the other. giffgaff also states that its Wi-Fi Calling is not supported abroad. If your house relies on Wi-Fi Calling because the indoor mobile signal is weak, check your exact model, firmware and account before changing providers. See our Wi-Fi Calling and VoLTE guide.
What happens when you run out of data?
On giffgaff, using up the data allowance or letting a plan expire can cause further usage to be charged from your PAYG credit. You can generally start the next plan early once you have less than 500MB remaining, but doing so replaces the current plan and forfeits any unused allowances. An auto-renewing or queued plan does not automatically start early just because the data runs out. With Lebara, check the specific plan's out-of-bundle charges and any available credit or spending controls before continuing to use data. This is why the smallest GB allowance is not always the cheapest usable choice.
For hotspot use, check enough UK data, the plan's tethering rules, local indoor signal and any relevant fair-use limits. The word “unlimited” does not guarantee unlimited roaming, an unrestricted speed in every location or a replacement for fixed broadband in all circumstances.
Who should choose which? Five realistic buying situations
1. Your home has usable Vodafone service but patchy O2. Start with Lebara's current SIM-only tariffs. Saving a small amount with giffgaff means little if O2 fails in your bedroom. Reverse the recommendation if O2 is the reliable one.
2. You regularly dial an eligible overseas number. Work out the actual number of minutes and the exact country/number type first. Lebara's included international calling can offset a domestic price difference. If you mostly call through WhatsApp on Wi-Fi, compare on UK data and signal instead.
3. You travel to the EU and need more than 5GB per trip. Shortlist a qualifying Lebara plan whose UK allowance also covers the intended roaming use. Verify the destination, data cap and eSIM activation conditions. If you are new to giffgaff, check UK-usage eligibility for included roaming; if you already use giffgaff, compare travel add-on costs before switching solely for one holiday.
4. You want to join with eSIM on a compatible phone not covered by Lebara's new-customer eSIM rollout. giffgaff is an especially relevant option because its app activation is available more broadly. If you require Lebara's Vodafone network, consider whether an eligible physical SIM works for your device instead; an eSIM-only handset changes the decision.
5. You need a lot of UK data but can commit for 18 months. Compare a suitable giffgaff fixed plan against Lebara's 12-month and rolling equivalents using the whole obligation, not just the lower displayed monthly charge. If you may move, travel for a long period or change networks soon, calculate early-exit costs before taking a discount. Do not assume the cheapest data plan is always the one with the most gigabytes.
If you want to compare two providers specialising more directly in international-calling bundles, Lebara vs Lyca Mobile addresses that different decision. This article stays focused on giffgaff versus Lebara, not the entire budget-SIM market.
Switching between giffgaff and Lebara without losing your number
Changing between O2-based giffgaff and Vodafone-based Lebara is a normal UK provider switch. To retain your mobile number, text PAC to 65075 using your existing SIM and give the code to your new provider. Do not cancel your current SIM before arranging the transfer. A PAC normally lasts 30 days; charges connected with a fixed-term agreement or phone finance may still apply. If you do not want to keep the number, the STAC to 75075 process is different. Our mobile number-switching guide explains both routes.
giffgaff vs Lebara: frequently asked questions
Are giffgaff and Lebara on the same network?
No. giffgaff uses O2 and Lebara uses Vodafone. Neither can be declared the stronger network inside every UK building. Compare local coverage before paying for a long contract.
Is Lebara always cheaper than giffgaff?
No. Their current allowances, promotions, renewal periods and contract commitments can differ. Compare like-for-like UK data and the full cost for the same usage dates, including any international calls or roaming you need. The live offers above are the correct place to check current prices.
Can giffgaff be better for unlimited data?
It can be if O2 serves your locations better, or if a suitable giffgaff deal has a lower full-term cost. But “unlimited” must be compared against actual network-management, roaming and minimum-term rules. Lebara can win the same comparison for another buyer.
Does Lebara include calls to any country for free?
No. Eligible Lebara SIM-only bundles include a specified allowance of international minutes for selected countries and number types; excluded numbers or exhausted allowances can cost extra. giffgaff normally charges international calls from the UK separately from its inclusive UK minutes.
Is Lebara better for EU roaming?
For eligible travellers needing more than 5GB of data on one trip, it often deserves the closer look because qualifying plans can include up to 30GB, compared with giffgaff's standard 5GB maximum. A small UK allowance lowers that roaming entitlement, and neither limit applies automatically to every destination.
Can I get an eSIM with either network?
Both support eSIM, but their activation routes differ. giffgaff offers app-based activation to eligible new and existing customers. Lebara's published new-customer eSIM availability is restricted to selected devices, with a separate process for existing customers. Check the exact phone and activation method before ordering.
Bottom line: buy for the network you can actually use, then compare the right product over the right number of payment periods. Lebara is a strong shortlist for eligible international calls and heavier included roaming; giffgaff can be the smarter choice for O2 coverage, accessible new-customer eSIM or an appropriately priced long-term data plan. Use the current cards and tariff-level View Deal links above for the final decision.
DealPriceCheck compares selected UK SIM offers rather than the entire market. Prices, eligibility and conditions can change; confirm the applicable details at checkout. Some links may earn a commission at no extra cost to you.