Best SIM-Only 5G Deals in the UK — July 2026
If you already own a 5G phone (or are planning to buy one outright), a SIM-only deal is almost always the most cost-effective way to get connected. You avoid the inflated monthly costs of bundled contracts, and with 5G now standard on virtually every plan, you're not compromising on speed. Here's our comprehensive roundup of the best SIM-only 5G deals available in July 2026.
At-a-Glance Comparison Table
| Provider | Data | Monthly Price | Contract | 5G Speed Cap | Link |
|---|---|---|---|---|---|
| Smarty | Unlimited | £16.00 | 1 month | None (full speed) | Visit → |
| Voxi | Unlimited | £20.00 | 1 month | None (full speed) | Visit → |
| Three | Unlimited | £20.00 | 12 months | None (full speed) | Visit → |
| giffgaff | Unlimited | £20.00 | 1 month | None (full speed) | Visit → |
| Vodafone | Unlimited | £25.00 | 12 months | None (full speed) | Visit → |
| O2 | Unlimited | £28.00 | 12 months | None (full speed) | Visit → |
| EE | Unlimited | £32.00 | 12 months | None (full speed) | Visit → |
Prices correct as of 1 July 2026. All plans include 5G at full speed. Always check the provider's website for the latest offers and terms.
In-Depth Provider Breakdown
Smarty — Best Value (£16/month, Unlimited)
Smarty runs on Three's network, which means you get access to one of the UK's fastest 5G infrastructures at a rock-bottom price. Their unlimited plan at £16/month is the cheapest truly unlimited 5G deal on the market. No speed caps, no lengthy contract (it's a rolling 30-day plan), and tethering is included at no extra cost. There's also a generous 12GB EU roaming allowance included. If you want maximum data for minimum money and Three's coverage works in your area, this is the pick of the bunch.
Voxi — Best for Social Media Users (£20/month, Unlimited)
Voxi piggybacks on Vodafone's 5G network and offers a compelling twist: "Endless Social Media" — meaning data used on apps like Instagram, TikTok, Snapchat, WhatsApp, and Facebook doesn't count towards your allowance. Their unlimited plan at £20/month essentially gives you infinite everything, including the social media zero-rating. No contract, cancel anytime, and Vodafone's 5G coverage has improved significantly, now reaching 78%+ of the UK population. The unlimited plan also includes unlimited music and video streaming data through their "Endless Video" perk.
Three — Best for Heavy Data Users (£20/month, Unlimited, 12-month)
Three has been the disruptor in UK 5G for several years, and their commitment to no speed caps (unlike some other networks that throttle 5G on cheaper plans) makes them a favourite among power users. Their £20/month unlimited plan includes 5G at full speed, Go Roam in 71 worldwide destinations, and access to Three's 5G Home Broadband-ready SIM. Three's 5G speeds regularly clock in at 165+ Mbps on average, and because they hold 100 MHz of contiguous 5G spectrum, their peak theoretical speeds are the highest of any UK network.
giffgaff — Best for Flexibility (£20/month, Unlimited, Rolling)
giffgaff operates on O2's network and is famous for its community-driven, no-frills approach. Their "always on" unlimited plan at £20/month gives you full-speed 5G with no contract lock-in. One unique feature: if you don't use all your data, giffgaff refunds the difference as credit. Coverage is solid via O2's infrastructure (76%+ population 5G), and giffgaff includes EU roaming up to 5GB. The trade-off is that O2's 5G speeds are typically slower than EE or Three, but for most everyday use, 100+ Mbps is more than enough.
Vodafone — Best All-Round Performer (£25/month, Unlimited, 12-month)
Vodafone offers a compelling 12-month plan at £25/month that includes full 5G speeds and their "VeryMe" rewards programme, which offers discounts on everything from cinema tickets to coffee. Vodafone's 5G network has improved markedly over the past 18 months, and they now boast strong coverage across cities and major transport corridors. They also offer an entertainment bolt-on — you can add YouTube Premium, Spotify, or Amazon Prime to your plan at a discounted rate. If you're already paying for one of those services separately, the bundle makes Vodafone excellent value.
O2 — Best for Perks (£28/month, Unlimited, 12-month)
O2 costs more than most competitors, but their O2 Priority app is genuinely valuable — offering early access to event tickets, free coffee from high street chains, and discounts on dining and shopping. Their unlimited 5G plan at £28/month includes EU roaming (up to 25GB), and O2's customer service consistently ranks highest in Ofcom's satisfaction surveys. 5G speeds on O2 average around 110 Mbps — slower than EE or Three — but entirely sufficient for streaming, gaming, and working on the go.
EE — Best for Speed and Coverage (£32/month, Unlimited, 12-month)
EE is the premium option, and the price reflects it. At £32/month for unlimited 5G data, it's the most expensive plan in our comparison. But you get what you pay for: EE's 5G network is consistently the fastest and most widely available in independent tests by RootMetrics and Opensignal, with average download speeds of 185 Mbps and the best rural coverage thanks to their 700 MHz spectrum holdings. EE also offers the most generous inclusive EU roaming (full allowance) and prioritises 5G traffic even during peak times. If you rely on mobile data for work or travel frequently to rural areas, EE is worth every penny.
What About Speed Caps?
One important thing to watch out for: while all the plans in our comparison table offer full, uncapped 5G speeds, some providers do cap 5G on their cheaper tariffs. For example, EE's entry-level "Essentials" plan caps 5G at 100 Mbps, and Vodafone's "Basics" tier limits 5G to 150 Mbps. Ofcom recommends always checking the small print — if a deal seems unusually cheap, there's probably a speed restriction applied. All the plans we've recommended above are full-speed, no-cap deals.
Which One Should You Choose?
If you want the absolute cheapest 5G with no compromises, Smarty at £16/month is unbeatable — just make sure Three's coverage is solid in your area first (use their coverage checker). For the fastest possible speeds and best coverage, EE at £32/month is the premium pick. Most people will find the sweet spot with Vodafone at £25/month — reliable speeds, good coverage, and useful entertainment perks that genuinely save money if you already subscribe to Spotify or YouTube Premium.
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Disclosure: We may earn commission from links on this page. Prices correct at time of writing (July 2026) and subject to change.