Unlimited Data SIM Only Deals
Compare the cheapest Unlimited Data SIM Only Deals from all major UK networks.
Why choose an unlimited data SIM?
An unlimited data SIM removes the one number everyone worries about. Stream, tether, hotspot and scroll without watching a meter — ideal for heavy streamers, commuters who live on mobile video, and anyone using their phone as a home broadband backup. Every deal above includes unlimited UK calls and texts alongside the unlimited data.
Check before you buy.
Not all unlimited plans are identical. A few networks sell speed-tiered unlimited plans, where a cheaper tier caps your maximum download speed — fine for social and music, worth avoiding if you tether or game. Check fair-use policies for tethering and roaming: most networks allow generous personal hotspot use, but EU roaming usually draws from a fair-use allowance rather than being truly unlimited abroad.
Who is unlimited best for?
If you use more than about 50GB a month, unlimited usually costs little more than a big fixed allowance and removes overage worry entirely. Lighter users often do better on a mid-size plan — compare against our full SIM only deals to see where the value sits.
The budget networks — Smarty and iD Mobile — are regularly the cheapest routes to unlimited, while Three has long made unlimited data its speciality.
Want to keep your current number? No problem.
Switching takes minutes: text PAC to 65075 from your current phone and give the code to your new network. The switch usually completes within one working day.