Compare Sky Mobile SIM Only Deals

Sky Mobile uses O2's network, which means your coverage for calls, texts and data lines up with O2 where you live and travel. If O2 has 5G in your area, you can use it on a plan and handset that support it. Coverage is the first thing to get right with any SIM, so check O2 signal at your key locations before switching.

Sky Mobile plans are designed to be flexible. You can mix and match your data, calls and texts and adjust the plan as your needs change, rather than being stuck with one fixed bundle. The standout is the Piggybank, which saves any data you do not use so you can dip into it another month. The live deals above show the current allowances and what you can tweak.

The Piggybank is the feature people remember Sky Mobile for: leftover data does not vanish at month end, it banks for later. On top of that, if you already have Sky TV or Sky broadband, you can unlock extra perks tied to your account. Exactly which extras apply depend on your Sky products and the plan you choose, so check the deal terms in the comparison above.

Sky Mobile makes a lot of sense if you are already a Sky TV or broadband customer, since the bundled perks add value you would not get elsewhere. The Piggybank also suits people whose data use swings month to month, as nothing goes to waste. If you have no other Sky products and just want the cheapest possible SIM, a more budget-focused O2-based network may edge it.

Sky Mobile, giffgaff, Lyca Mobile and Tesco Mobile all share O2's network with O2 itself, so coverage is much the same. They part ways on the extras: Sky Mobile rolls over your data and rewards Sky households, giffgaff leans on flexible rolling plans, Lyca Mobile on cheap international calls, and Tesco Mobile on Clubcard points. Pick the perk that fits your life.