giffgaff is owned by Virgin Media O2 and runs on O2's network. In its own words, "we're powered by the O2 network". So a giffgaff SIM gets exactly the same coverage as an O2 SIM. The two brands are run very differently, though. giffgaff keeps costs down with no phone line and a member community that answers questions. O2 charges more but adds shops, perks and higher roaming limits.
How do giffgaff and O2 compare at a glance?
The table pulls prices and price rises from our live deal feed, so it matches the deals on our comparison pages today. The roaming, eSIM and exit-fee rows come from each network's own pages.
| Feature |  giffgaff |  O2 |
|---|---|---|
| Owned by | Virgin Media O2 | Virgin Media O2 |
| Runs on | O2's network | Its own network |
| SIM only from | £6 a month | £7 a month |
| Cheapest unlimited data | £14 a month | £23.99 a month |
| Capped data plans | 2GB to 200GB, plus unlimited | 3GB to 250GB, plus unlimited |
| Contracts in our deals | 30-day and 18 months | 30-day, 12 months and 24 months |
| Scheduled price rises | None scheduled on current deals | 16 of 20 deals: up £2.50 a month from April 2027 |
| EU roaming | Included. Up to 5GB, with top-up add-ons after that. | Included. Up to 25GB, then charged per GB. The only big network with no daily fee. |
| eSIM | Yes. Activation is app-only; there are no QR codes. | Yes. Choose eSIM at checkout; pay as you go eSIMs are sold in O2 stores. |
| Leaving early | Monthly plans: nothing. 18-month plans: half the monthly price for each month left. | 30-day: nothing. 12 or 24 months: the airtime left, less 4%. |
| Deals | See giffgaff deals | See O2 deals |
Live rows show the deals in our feed at the last refresh, not every plan a network sells. EU roaming was checked against each network’s own pages on 28 August 2026, eSIM on 26 August 2026, and ownership and exit terms on 23 September 2026.
Is giffgaff cheaper than O2?
For the same data, yes, by a wide margin in our feed. When we checked on 23 September 2026, giffgaff's cheapest unlimited data plan was £14 a month on an 18-month contract, or £20 on a monthly rolling plan. O2's cheapest unlimited plan was £23.99 a month on 24 months, or £38 on a 30-day plan.
Over a full contract the gap grows. giffgaff's £14 deal comes to £252 over 18 months. O2's £23.99 deal comes to £630.76 over 24 months, because it rises twice in that time. Those are different term lengths, but even month by month, giffgaff costs less on the same masts.
The saving pays for real differences, which the rest of this page covers. Our data allowance guide helps you check how much data you actually need before you compare.
Do you need a contract, and can the price rise?
giffgaff sells two kinds of plan. Monthly rolling plans can be changed or cancelled at any time. Its 18-month contracts cost less, and giffgaff's terms let you switch between plans each month "without re-setting the term". Its deals page promises a "Price lock" with "no mid-contract price rises" on those contracts. Its general terms still let it change prices with advance notice, so the promise is the part to hold it to.
O2 sells 30-day, 12-month and 24-month SIMs. On the fixed terms, the price rises by an amount set out when you sign: "Each April, your airtime plan will increase by £2.50 for voice plans and 75p for data-only and smartwatch plans". You'll know the full cost up front, but it will go up. Our price rise guide explains the rules on both.
Leaving early costs very different amounts. On giffgaff's 18-month plans, the charge is half your monthly price for each month left. On a £14 plan with ten months to go, that's £70. O2 charges the airtime left, less 4%, so on a £23.99 plan with ten months to go it's about £230.
Will giffgaff run a credit check?
giffgaff doesn't for SIM plans. Its help pages say: "They'll only carry out a credit check if you buy a phone on a contract with a loan". That covers its 18-month plans too.
If your credit history is thin or patchy, giffgaff's approach removes one barrier to getting a SIM on the same network.
What do you get with O2 that giffgaff doesn't offer?
O2's extras are the main reason to pay more. Priority is a free rewards app with weekly offers from brands such as Greggs, cinema deals and 48-hour ticket presales. Multisave takes 20% off the airtime of each extra eligible line on your account, up to 20 numbers. And O2's Plus and Ultimate plans roll unused data over for one billing cycle.
Roaming is the other big difference. O2 includes EU roaming up to 25GB a month. giffgaff includes it up to 5GB, then charges 10p per extra MB, according to its plan pages. A heavy data user abroad could burn through giffgaff's 5GB in a few days of maps and streaming.
giffgaff has its own reward scheme, Payback. Members earn points for recommending friends, answering questions in the community and suggesting ideas. Each point is worth 1p, paid out in June and December as PayPal cash, credit or a charity donation. Our EU roaming guide compares both networks' travel terms with everyone else's.
How does customer service compare?
This is where the two differ most in how they work. giffgaff has no phone line. You get help through its online help hub, an AI assistant that hands over to human agents, and its member community forum. O2 has phone support and shops across the country.
On Ofcom's figures, giffgaff's approach holds up well. Ofcom recorded 1 complaint per 100,000 giffgaff customers from January to March 2026, and 3 for O2, against an industry average of 2. Ofcom treats both as comparable with the average. In Ofcom's 2024 customer service survey, 94% of giffgaff customers were satisfied overall, compared with 85% at O2 and an 88% average.
If you'd rather call someone or walk into a shop, O2 gives you that. If you're comfortable with chat and a community forum, giffgaff's satisfaction scores suggest the model works for most of its members.
Is coverage the same on giffgaff and O2?
Yes. Both use O2's masts, so Ofcom's January 2026 figures for O2 apply to both. They show 4G at 99.6% of premises outdoors and 95.5% indoors, and 5G at 86.2% outdoors. Indoor 4G in rural areas is lower, at 82.0%.
Check your postcode on our mobile coverage map. Whatever it shows for O2 is what giffgaff gets too.
Why you might choose giffgaff
- You want O2's coverage for much less each month.
- You want a price lock on an 18-month plan, or no commitment at all.
- You'd rather avoid a credit check.
- You're happy getting help online rather than by phone.
Why you might choose O2
- You travel in Europe and use more than 5GB of data while you're away.
- You'd use Priority's offers, or add several lines through Multisave.
- You want phone support and shops you can visit.
- You're on a capped plan and want unused data to roll over.
How do you switch between giffgaff and O2?
Your signal won't change, since both use O2's masts. Text PAC to 65075 from your current phone. The code arrives within a minute, and the switch completes within one working day of giving it to your new network, under Ofcom's rules. Our switching guide covers the details.
Check your exit fee first if you're mid-contract. Our guide to leaving early sets out each network's formula.
Sources and how we checked
Prices, contract lengths and scheduled rises come from our live deal feed and refresh whenever the site updates. We checked giffgaff's SIM deals page, terms and conditions and credit check help, and O2's price guide and Multisave page, on 23 September 2026. Service figures come from Ofcom's telecoms complaints data and Comparing Customer Service report.