giffgaff vs VOXI: which SIM suits you?
Both are no-fuss SIM-only brands owned by big networks. giffgaff runs on O2, and VOXI on the combined Vodafone and Three network. The real differences are social-media data, roaming and contract length.
Quick answer: pick VOXI if most of your data goes on social apps, because VOXI says social media data is unlimited on every plan. Pick giffgaff if you travel in Europe, because giffgaff includes up to 5GB of EU roaming on every plan, while VOXI needs a paid roaming pass. Signal matters most: giffgaff uses O2, and VOXI uses Vodafone and Three.
Facts from giffgaff.com and voxi.co.uk, read 3 Nov 2026 · Last updatedWe don't show giffgaff or VOXI prices: neither has a partner feed we can check, and we only show prices we've checked. SimSift earns no commission from either. How we make money.
giffgaff
- Network: O2
- Contract: Monthly rolling plans plus 18-month plans; "switch up, down or cancel whenever you fancy"
- Social media data: Counts towards your data
- Music and video data: Counts towards your data
- EU roaming: Up to 5GB across 37 EU destinations, on every plan
- Mid-contract price rises: Its plans page says "No mid-contract price rises"
- Extras: Which? Recommended (giffgaff's own claim)
VOXI
- Network: The combined Vodafone and Three network ("The Nation's Network")
- Contract: Rolling 30-day plans, "no contract, cancel any time"
- Social media data: Unlimited UK use of selected social apps on every plan
- Music and video data: Unlimited music and video apps on some higher plans
- EU roaming: Buy a European Roaming Pass
- Mid-contract price rises: Not stated on the pages we read
- Extras: VOXI Drop monthly rewards
Sources: giffgaff SIM-only plans, giffgaff roaming, VOXI and VOXI terms, read 3 Nov 2026. Offers change, so check both sites before you switch.
Want Vodafone's network for less?
VOXI runs partly on Vodafone. Lebara uses Vodafone too, and we check its prices daily: 5GB 30-day rolling at £5 a month, 30GB 30-day rolling at £10 a month, 50GB 30-day rolling at £15 a month. See Lebara's checked plans (affiliate links, marked Ad).
Questions people ask
Which network does giffgaff use?
O2. giffgaff says it "runs on O2's mobile network".
Which network does VOXI use?
VOXI says it runs on "The Nation's Network", the combined Vodafone and Three network.
Does VOXI include free social media data?
Yes. VOXI says every plan includes unlimited data in the UK for selected social apps, such as Instagram, Snapchat, WhatsApp and Facebook. Other browsing uses your general data.
Can I use my data in Europe?
giffgaff says every plan includes up to 5GB of roaming data across 37 EU destinations. VOXI says you must buy a European Roaming Pass to roam.
Do I need a credit check?
giffgaff says credit checks are "not our business". VOXI's SIM plans are 30-day rolling subscriptions paid online. Its phone finance does involve a credit check.
Can I keep my number?
Yes. Text PAC to 65075 for free and give the code to your new network.