Network vs network
giffgaff vs O2
Same masts, different deals. We compare price rises in pounds, roaming, credit checks and today’s cheapest SIMs on both.
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Do they use the same masts?
Yes — coverage is effectively the same, so choose on price and extras.
Which one raises prices?
giffgaff: No annual rise. O2: +£2.50 every April.
Which is better abroad?
giffgaff: EU included, 5GB. O2: EU included, 25GB.
giffgaff£240
O2£228Cheapest SIM with 10GB or more × 24, plus April rises
Live prices; rises estimated for a plan starting this month.
Over 24 months, the cheapest 10GB+ SIM costs £240 on giffgaff and £228 on O2 once April rises are added — O2 is £12 cheaper. Both run on the same masts.
Prices checked 28 October 2026 · facts checked monthly · How we compare
giffgaff vs O2, side by side
| giffgaff | O2 | |
|---|---|---|
| Masts | O2 | Own masts |
| Annual price rise | No annual rise | +£2.50 every April |
| Roaming | EU included, 5GB | EU included, 25GB |
| Credit check | None | Hard check |
| eSIM | Yes | Yes |
| Wi-Fi Calling | Yes | Yes |
| Ofcom complaints per 100k (Q1 2026) | 1 | 3 |
| Cheapest SIM, 10GB+ | £8 a month | £7 a month |
| Cheapest SIM, 30GB+ | £8 a month | £8 a month |
| Cheapest SIM, Unlimited | £25 a month | £23 a month |
Highlighted = better on that line. Facts from network terms and Ofcom; prices live.
Our verdict
On price, O2 comes out ahead for a typical 10GB+ SIM: £12 less over two years once April rises are counted (giffgaff rises add about £0, O2’s about £60).
Because both use the same masts, coverage is identical — the choice comes down to price, price rises and extras.
Pick giffgaff if…
- You want a price that doesn’t rise every year
- You want to avoid a credit check
giffgaff and O2 SIM only deals, live
FAQ
giffgaff vs O2 questions
Is giffgaff or O2 cheaper?
O2, today: the cheapest 10GB+ SIM costs £7 a month, and over 24 months with April rises the gap is £12.
Do giffgaff and O2 use the same network?
Yes, coverage is the same.
Which has better roaming?
giffgaff: EU included, 5GB. O2: EU included, 25GB.
Can I switch from giffgaff to O2 and keep my number?
Yes. Text PAC to 65075 from your giffgaff phone, give the code to O2, and the number moves within one working day.