An unlimited plan removes the one thing people worry about most — running out. But networks price their unlimited plans from very cheap to quite expensive, and the difference is in conditions that rarely make it onto the deal card.
The three kinds of unlimited
- Genuinely unlimited. No data cap, full speed, no deprioritisation. Usually the host network's own top tier, or a virtual operator's most expensive plan.
- Unlimited with a speed cap. No cap on volume, but download speed limited to, say, 2Mbps or 10Mbps. Fine for messaging, music and standard-definition video; frustrating for anything else. Common on the cheapest unlimited SIM-only deals, and the reason they are cheap.
- Unlimited with fair use or deprioritisation. Full speed, but the network reserves the right to slow you at busy times once you have used a large amount in a month, or to act if usage is "not consistent with personal use" — typically aimed at people running a whole household off a phone. For most users this never triggers.
Where to find the conditions
The plan's terms page, usually under a "fair usage" or "traffic management" heading. Look for a speed figure (any number of Mbps means a cap), a monthly volume after which management kicks in, and the tethering policy — some unlimited plans limit how much of the allowance you can share with a laptop.
Roaming
Unlimited almost never means unlimited abroad. Plans that include EU roaming apply a fair-use limit there — often somewhere between 12GB and 50GB a month — after which you are charged or slowed. If you travel a lot, this number matters more than the headline.
Do you need unlimited at all?
Often not. A large fixed allowance without a speed cap can be both cheaper and faster than a capped unlimited plan. Work out your real usage (here is how), add headroom, and compare that against the unlimited options. Our unlimited SIM-only filter shows them all; the speed conditions are on the retailer's page when you click through.