What SIM only actually means
A SIM only plan provides data, minutes, and texts on a SIM card — no handset included. It's usually the cheapest route if you already own a compatible phone, on any of the 7 networks covered on this site.
30-day rolling vs 12-month
30-day rolling gives maximum flexibility — cancel anytime with 30 days' notice. 12-month terms typically offer better value per month in exchange for that shorter-term flexibility.
Unlimited data SIM only
Most major UK networks now offer unlimited data SIM only tiers for heavy users who don't want to track a monthly allowance.
Data-only SIMs
Data-only SIMs (no calls or texts) suit tablets, mobile broadband devices, and smartwatches that just need a data connection.
Comparing SIM only across networks
See each network's dedicated guide — Three, O2, EE, Tesco Mobile, Vodafone, Sky Mobile, iD Mobile — for tier-specific detail.
Independent guidance notice: Onuhiowise (onuhiowise.online) is an independent information and guidance website covering all major UK mobile networks equally — Three, O2, EE, Tesco Mobile, Vodafone, Sky Mobile, and iD Mobile. We are not any of these companies, not a reseller, not an agent, and not an authorised partner of any of them. We do not sell SIM cards, contracts, or airtime, and we do not display or quote pricing anywhere on this site. If you contact us by phone or form, you are reaching Onuhiowise's own independent guidance team — never a network's official customer service line. Our team will always introduce themselves as Onuhiowise, an independent service, and will never claim or imply that we are O2, Three, EE, Tesco Mobile, Vodafone, Sky Mobile, iD Mobile, or any other network. Network names and colours used on this site are trademarks of their respective owners, used only so you know which network a page is about — this does not imply any partnership or endorsement. Always confirm final pricing, contract terms, and account-specific matters directly with your network.