cheap 5G sim only deals UK 2025

Cheap 5G SIM-Only Deals in the UK (2025): Best Budget Options

What’s going on with 5G SIM-only in the UK right now

With 5G rollout now widespread across most parts of the UK, 2025 has brought a wave of very competitive SIM-only deals that support 5G. These plans are offered by both major networks and MVNOs (Mobile Virtual Network Operators), meaning there are real opportunities to get solid data allowance without paying for a full contract phone. The trick is picking a plan where the data, commitment length, and cost align with what you actually use.

Why the prices are so attractive now

• MVNOs run on established networks (EE, Three, Vodafone), so they can price aggressively.
• More 5G-ready SIMs: as 5G matures, operators are incentivised to convert users to data-heavy SIMs.
• Deals with cashback or reward structures are more common, driving effective cost down.

Top Budget 5G SIM-Only Deals to Consider

Here are some of the best-value 5G SIM-only deals in the UK in 2025 (based on publicly available sources):

1. iD Mobile – 150 GB, 12-month plan
   Approximately **£12/month**. This is great if you want a high-data plan without a long contract.
2. ASDA Mobile – 25 GB 5G
   A 12-month SIM-only contract for about **£8/month**, ideal for moderate data users.
3. Three Mobile – 30 GB 5G
   A 12-month deal with **£8/month** pricing. Good balance of data and cost.
4. Lebara – 5G from £4.50
   This very low-cost deal is available with some restrictions, but if your usage is light it’s one of the cheapest 5G options.

Other Deals Worth Keeping an Eye On

- Some MVNOs occasionally offer **cashback-backed 5G plans**, which reduce the effective monthly rate. - For more data (60-120GB range), it's worth checking regularly: SIM-only deals shift quickly as new promos launch.

Things to Watch Out For (Pitfalls)

• Coverage and 5G strength: Just because a plan supports 5G doesn't mean coverage is excellent everywhere — check whether your area has good 5G from the underlying network.
• Contract length: Deals locked into 12 or 24 months may be cheaper per month, but less flexible if your needs change.
• Cashback claims: Many of the lowest “effective” prices assume you submit cashback claims — make sure you understand how and when to do that correctly.
• Speed or fair-use caps: Very cheap MVNO plans might impose “soft” caps or degrade performance after a certain usage threshold.

How to Choose the Right 5G SIM-Only Deal

Here’s a checklist I used (from personal experience) when picking a 5G SIM-only plan:

1. Estimate realistic data usage: do you need 20 GB, 50 GB, or more? My browsing + streaming habits roughly shaped my choice.
2. Decide on contract commitment: 12-month versus no contract — weighing savings vs flexibility.
3. Use comparison tools, then double-check the MVNO’s own site for live promos.
4. Look for cashback or sign-up rewards; they often make the "headline" monthly cost misleadingly low.
5. Read the small print for network coverage, throttling policy, and “fair-use” terms.

Quick Test After Activation

Once you activate the SIM, run a speed test using 5G: I used the Speedtest app and monitored data usage for a week. Then, set a reminder a month before your plan ends (if on contract) so you can re-evaluate or switch.

Why Now Is a Great Time for 5G SIM-Only in the UK

The 5G market has matured, and competition is real — you’re no longer paying a premium for “future-proof” data. With aggressive MVNO offers and more 5G-capable phones in use, cheap SIM-only plans make more sense than ever. If you're willing to commit (or claim cashback), you can get a deal that’s genuinely good value.