Unlimited data is usually sold attached to something: a two-year term, a handset you are paying off, a credit check that decides whether you qualify. Separating the allowance from the agreement changes what it is for. An unlimited data SIM on a thirty-day plan is a thing you can try for a month, keep for a year, or drop the moment your usage settles — and that flexibility is as much the product as the data.
UK Plan Unlimited sits at the top of the pay as you go range. It lists at £25.00 and is currently £12.50, half price for the first month, and the standard price is what the line runs at from the second month onward. Alongside the data it carries unlimited UK calls and texts, 100 international minutes, 5G and an instant digital SIM option, plus EU and India roaming capped at 35GB — the largest roaming allowance in the range.
There is no contract behind it, no termination fee and no credit check. Thirty days, then a decision. That is the whole shape of an unlimited data plan bought this way.
The deals page says that unlimited allowances are subject to a fair usage policy, and the policy has its own page. That is worth reading rather than skipping, because "unlimited" on any network in Britain means unlimited within a policy, and knowing where the policy sits is the difference between a plan that suits you and one that frustrates you.
The visible limit is the roaming cap: 35GB abroad, which is generous but finite. Domestically the policy exists to catch commercial-scale use rather than ordinary heavy use, so streaming, tethering and video calls in normal quantities are what the plan is for. If your pattern is genuinely industrial — running a business connection off a handset, for instance — read the policy first rather than assuming.
It is worth being honest about this, because the tier below is capable. UK Plan Mega Plus carries 120GB, lists at £20.00 and is currently £10.00. For the overwhelming majority of single users, 120GB is not a ceiling they will meet — it is roughly four hours of high-definition video every day for a month.
Below that, UK Plan Super Extra carries 75GB, listing at £15.00 and currently £7.50, and National Plus carries 30GB, listing at £10.00 and currently £5.00. The honest test is last month's figure on your current phone. If it came in under 60GB, the unlimited tier is buying you reassurance rather than data, and reassurance is a legitimate thing to buy — just know that is what it is.
Three patterns justify it without argument. A household sharing one connection across several devices, where no single person's usage explains the total. A commuter who streams video both ways on a line with patchy wi-fi. And anyone who tethers a laptop for work, which is the fastest way to turn a generous allowance into a spent one. If one of those is you, the unlimited SIM only plan stops being a luxury and starts being the only tier that does not need managing.
That ability to move is what makes a no contract data plan worth more than the price difference suggests over a year.
Unlimited without a contract is the version of this that makes sense: take it for the months you need it, step down to 120GB or 75GB for the months you do not, and let the thirty-day cycle do the work. Check last month's usage before you decide, and read the fair usage page once so the word means what you think it means.
The current and standard price on the unlimited tier, and the fair usage policy itself, are both published by Lycamobile.
Work out what else you are over-buying with a look at OrganizeTrip.
