Last updated: Thursday 12 November 2026
Tesco Mobile or giffgaff: which is cheaper? giffgaff, for most people. On 12 November 2026, giffgaff’s 40GB plan was £8 a month on an 18-month contract with no credit check, while Tesco Mobile’s cheapest comparable deal was 75GB for £12 a month with a Clubcard on a 24-month contract. Both run on O2’s network, so the signal is the same. Tesco Mobile wins if you shop at Tesco and want a lot of data: its Black Friday Clubcard Price of £14 a month for 250GB is frozen for 24 months. It also scored slightly higher for customer satisfaction in Which?’s January 2026 survey, 81% against giffgaff’s 79%.
This SwitchSquid guide compares price per GB, contracts, Clubcard perks, roaming and Black Friday timing. Tesco Mobile prices come from its Black Friday SIM only page and offers page, which say the Clubcard Prices run from 2 to 30 November 2026, subject to availability, plus Regular Prices on the same offers page on 12 November 2026. giffgaff prices are from giffgaff’s contract SIM page on 12 November 2026. We don’t have a commission arrangement with Tesco Mobile, so the buttons on this page go to giffgaff plans. We may earn a commission if you buy through them; it doesn’t change the price you pay.
giffgaff 40GB for £8 a month on the same O2 network
- 40GB of 5G data with unlimited UK calls and texts for £8 a month on an 18-month plan, £144 in total
- No credit check, and giffgaff says there are no mid-contract price rises on 18-month plans bought before the end of 2026
- Main limitation: an 18-month commitment, and the 40GB is a promotion: giffgaff shows it as a 6GB plan with 34GB extra data
Tesco Mobile vs giffgaff at a glance
Tesco Mobile | giffgaff | |
|---|---|---|
Network | O2 | O2 |
Cheapest big-data deal | 250GB for £14 a month with a Clubcard, 24 months | 200GB for £12 a month, 18 months (Black Friday, activate by 7 December 2026) |
Cheapest everyday deal | 12GB for £9.50 a month with a Clubcard, 12 months | 40GB for £8 a month, 18 months |
Rolling monthly option | Pay as you go | Monthly rolling plan from 20GB for £10, or pay as you go 15GB for £10 |
Price rises during the contract | None on Clubcard Prices; set rises each April otherwise | None on 18-month plans |
Credit check | Yes, on pay monthly | No |
EU roaming | Home From Home in 48 destinations at no extra cost | Up to 5GB of roaming data in 37 EU destinations, on every plan |
Which? customer score (January 2026) | 81%, 2nd of 15 | 79% |
Extras | Clubcard points on your bill, bonus points on some plans | Payback rewards for helping in the community |
Which? scores are from its January 2026 survey of 5,137 mobile customers, as reported by ISPreview. The giffgaff 200GB price is a Black Friday promotion; after the 18 months the plan goes back to its standard allowance.
Price per GB: who gives more data for your money?
Because both networks use O2, price is usually the deciding factor. Here are the main deals side by side, with the total you pay over the minimum term.
Deal | Data | Monthly price | Contract | Total over the term | Price per GB |
|---|---|---|---|---|---|
giffgaff 200GB (Black Friday) | 200GB | £12 | 18 months | £216 | 6p |
Tesco Mobile 250GB (Clubcard Price) | 250GB | £14 | 24 months | £336 | 5.6p |
Tesco Mobile 75GB (Clubcard Price) | 75GB | £12 | 24 months | £288 | 16p |
giffgaff 40GB | 40GB | £8 | 18 months | £144 | 20p |
giffgaff 100GB | 100GB | £15 | 18 months | £270 | 15p |
Tesco Mobile 12GB (Clubcard Price) | 12GB | £9.50 | 12 months | £114 | 79p |
Tesco Mobile 75GB (Regular Price) | 75GB | £16.25, rising each April | 24 months | £390 before April rises | 22p |
Tesco Mobile Regular Prices on its offers page (Tesco Mobile, 12 November 2026) include 12GB at £11 a month on a 12-month contract, 75GB at £16.25 a month on 24 months (£390 over the term before any April rises) and 250GB at £22.50 a month on 24 months (£540 over the term before any April rises). Tesco’s own Clubcard Prices page says the basic monthly price on a Clubcard Price deal is frozen for the length of the contract.
The pattern is clear. For light and medium users, giffgaff is cheaper: 40GB for £8 is less than Tesco’s 12GB Clubcard Price. For heavy users who shop at Tesco, the 250GB Clubcard Price is the cheapest data per GB in this comparison, but it ties you in for 24 months, six months longer than giffgaff. Over two years, Tesco’s 250GB costs £336. giffgaff’s 200GB costs £216 for its 18 months, and you are then free to leave.
Coverage: is there any difference?
No. Tesco Mobile and giffgaff both use O2’s masts for 4G and 5G, so coverage is the same in any given place, including 5G where O2 has switched it on and you have a 5G phone. If O2 is strong at your home and work, both are good choices. If it is weak, neither will fix that, and you would be better looking at a SIM on EE, Vodafone or Three.
Use O2’s or Tesco Mobile’s coverage checker for your postcode before you buy. Tesco Mobile gives you 14 days to cancel a new contract, and giffgaff’s monthly rolling plans and pay as you go options let you test the signal for a month without signing up for 18 months.
Contracts, credit checks and price rises
This is the biggest practical difference. giffgaff’s 18-month plans have no credit check and no mid-contract price rises. If you leave early, giffgaff charges 50% of the monthly price for each remaining month, under its terms. It also sells a monthly rolling plan, from 20GB for £10, and pay as you go, including 15GB for £10, that you can stop at any time.
Tesco Mobile’s pay monthly SIMs need a credit check and run for 12 or 24 months. Clubcard Price deals are frozen for the minimum term. Plans without a Clubcard Price go up every April by an amount shown in pounds and pence when you buy, as Ofcom’s rules have required since January 2025. The Clubcard is free to join, so there is little reason to take a Tesco plan without one if a Clubcard Price is available.
giffgaff 100GB for £15 a month, £270 over 18 months
- 100GB of 5G data with unlimited UK calls and texts for £15 a month on an 18-month plan
- Against Tesco Mobile’s 75GB Regular Price of £16.25 a month (Tesco Mobile, 12 November 2026)
- Main limitation: giffgaff’s Black Friday 200GB plan at £12 a month gives more data for less, so check giffgaff’s page for that offer first; this button opens the 100GB plan
Clubcard perks: what Tesco Mobile adds
Tesco Mobile is the only one of the two that links to a loyalty scheme. You collect Clubcard points on your monthly bill, and Tesco says some 12-month SIMs earn an extra 300 points in any billing month when you spend £50 or more in one Tesco shop (up to 3,600 points, worth £36), or 250 extra points when you spend £30 or more on fuel at Tesco. If you shop there every week, that can make a real dent in the cost. If you don’t, it is worth nothing.
giffgaff’s version is payback, which rewards members for helping others on its community forum. For most people it is small change.
Roaming and eSIM
Tesco Mobile’s Home From Home lets you use your allowance in 48 destinations, including the EU, at no extra cost. giffgaff includes up to 5GB of roaming data in 37 EU destinations on every plan, which is plenty for a week away but can run short on a longer trip. Outside those areas, both charge extra or sell add-ons.
giffgaff lets you switch to an eSIM in its app, and Tesco Mobile supports eSIM on compatible phones. If you have a dual-SIM phone, you can keep one network on a physical SIM and add the other as an eSIM.
Black Friday timing
Both networks already have their Black Friday deals on sale. Tesco Mobile says its Clubcard Price SIM deals run from 2 to 30 November 2026, subject to availability, and that offers may change during the event. giffgaff’s 200GB for £12 has to be activated by 7 December 2026, and its 40GB for £8 is a data-boost promotion on its 6GB plan. If one of these is the deal you want, there is little to gain by waiting until 27 November.
Which should you choose?
Choose giffgaff if you want the lowest price for up to about 100GB, no credit check, a shorter contract or the option to go month to month.
Choose Tesco Mobile if you shop at Tesco, want 250GB or more for £14 a month frozen for two years, or value its slightly higher Which? score and Home From Home roaming.
Look elsewhere if O2 is weak at your address. Our VOXI vs giffgaff guide compares giffgaff with a SIM on Vodafone’s network.
How to switch between Tesco Mobile and giffgaff
Check when your current contract ends, and any early exit charge.
Text PAC to 65075 to get your switching code, free and instantly, if you want to keep your number.
Order your new SIM or eSIM and give the code when you activate it, or within 30 days.
Your number moves within one working day, and your old contract ends automatically.
Sources
Tesco Mobile: Black Friday SIM only deals and Tesco Mobile offers (Clubcard Prices from 2 to 30 November 2026)
giffgaff: SIM only contracts (12 November 2026)
Our verdict: giffgaff is the better buy for most people on O2, with 40GB for £8 and no credit check. Tesco Mobile is worth it for Tesco shoppers who need a lot of data, thanks to 250GB for £14 a month frozen for 24 months.
Prefer no contract? giffgaff 15GB for £10 for one month
- 15GB with unlimited UK calls and texts for £10 on pay as you go, with no contract
- Same O2 network as Tesco Mobile, so it is an easy way to test giffgaff’s signal before committing
- Main limitation: giffgaff’s monthly rolling plan gives 20GB for the same £10 if you’re happy for it to renew automatically.
FAQ
Is Tesco Mobile or giffgaff cheaper?
giffgaff is cheaper for most data sizes. On 12 November 2026 it offered 40GB for £8 a month and 200GB for £12 a month on 18-month plans. Tesco Mobile’s best value is 250GB for £14 a month with a Clubcard on a 24-month contract, which is cheaper per GB but longer.
Do Tesco Mobile and giffgaff use the same network?
Yes. Both run on O2’s network for 4G and 5G, so coverage and signal are the same wherever you are. Check O2 coverage at your postcode before you buy either.
Does giffgaff work on a Tesco Mobile phone?
Usually, yes. UK networks have not been allowed to sell locked phones since December 2021, and giffgaff uses the same O2 network, so a giffgaff SIM should work in a Tesco Mobile phone bought since then. Older Tesco phones may need unlocking first.
What are the disadvantages of Tesco Mobile?
Its best prices need a Clubcard and usually a 24-month contract, and plans without a Clubcard Price rise every April. Pay monthly contracts also need a credit check. Coverage depends entirely on O2.
What are the disadvantages of giffgaff?
giffgaff’s cheapest deals need an 18-month commitment, and leaving early costs 50% of the remaining monthly charges. Its customer support is mostly online and through its community. Like Tesco Mobile, it relies on O2’s coverage.
Do Tesco Mobile Clubcard Prices go up mid-contract?
No. Tesco Mobile says the basic monthly price on a Clubcard Price deal is frozen for the length of your contract. Plans without a Clubcard Price rise each April by an amount shown in pounds and pence when you buy.
Which is better for roaming, Tesco Mobile or giffgaff?
Tesco Mobile’s Home From Home covers 48 destinations at no extra cost, which is wider than giffgaff’s EU roaming. giffgaff includes up to 5GB of roaming data in 37 EU destinations on every plan.
