Guides, reviews and comparisons for UK SIM only deals, networks and mobile contracts.
The best of the big four is the one that works at your address. Here's how coverage, MVNO hosts and mid-contract rises should decide it, not a national ranking.
Under £10 can be great value for Wi-Fi-first users — or a false economy if the plan is too small, on the wrong network, or hides price rises. Here's how to compare live deals honestly.
giffgaff is the community-powered O2 MVNO: 30-day goodybags, no credit check on typical SIM only plans, and credit back for unused data. Here's a straight look at whether it's any good.
A cheap month-one SIM can cost more over a year if the contract allows annual rises. Here's how to spot those clauses and when a rolling plan is the safer choice.
20GB to 40GB is the middle of the SIM only market. Here is how to compare price per GB, coverage, contract length, 5G, roaming and price rises, with live deals rather than fixed prices.
Talkmobile is the budget Vodafone MVNO: same coverage as a standard Vodafone contract, aimed at leaner pricing rather than streaming or international extras. Here's a straight look at whether it's any good.
Poor credit or a thin file does not mean you cannot get a SIM. Here's how no-credit-check rolling plans work, which networks offer them, and how to compare live deals without risking hard searches.
Lebara is the MVNO built around international calling: included minutes abroad and standard EU roaming, backed by phone and live chat support. Here's a straight look at whether it's any good.
Smarty is Three's own no-frills MVNO: competitively priced with account-credit data rollover, but online-only support won't suit everyone. Here's a straight look at whether it's any good.
VOXI is Vodafone's own younger-skewing MVNO. Its Endless feature can make a small data allowance go a long way for streamers, but EU roaming and app coverage vary by plan. Here's a straight look at whether it's any good.
iD Mobile is Carphone Warehouse and Currys' own MVNO, running on Three's network with data rollover and in-store support. Here's a straight look at whether it's any good.
VOXI and Lebara share the same network infrastructure and both skip the credit check, so the real choice comes down to what each plan actually rewards, not coverage.
"Cheapest" changes daily, so a blog post that quotes a fixed price is out of date within a week. Here's how to actually evaluate SIM only deals, and where to check what's cheapest right now.
Ofcom's text-to-switch system means getting a PAC code takes one text and a few minutes. Here's the complete step-by-step guide to switching networks and keeping your number.
giffgaff, Smarty and VOXI don't own any masts. They rent network capacity from the four real UK networks at wholesale rates, which is why they can charge so much less, with identical coverage.
Unlimited data makes sense for heavy streamers, mobile hotspot users and anyone without home broadband. Here are the cheapest current unlimited SIM deals with live prices.
SIM only is almost always cheaper if you own a phone already. But if you need a new device, the right answer depends on the total cost. We crunch the numbers with live prices.
Not everyone needs unlimited data. If your phone is mostly on Wi-Fi, you could be overpaying. Here are the cheapest current SIM deals under 10GB with live prices.
Both giffgaff and Smarty are popular no-credit-check MVNOs running on the UK's major networks. We compare them on price, coverage, data rollover and customer service.