Last updated: March 2026 • Reviewed by Compare The Networks
Why Businesses Choose Three
Three is the value champion of UK business mobiles. If your priority is getting the most data for the least money, Three is hard to beat. Their unlimited data SIM only plan at £10/month is less than half the price of equivalent plans on EE or O2.
Key advantages for business users:
- Cheapest unlimited data — £10/month SIM only, the lowest in the UK
- Strong 5G in cities — 300+ locations covered with average speeds of 80-150 Mbps
- Simple pricing — transparent plans with no hidden charges
- 5G at no extra cost — included on all plans with compatible handsets
- EU roaming included — use your UK allowance in EU countries
Three Business Plan Comparison
| Plan | Data | Contract | Monthly Cost | Best For |
|---|---|---|---|---|
| SIM Only Starter | 1GB | 24 months | £6/mo | Basic calling & texting |
| SIM Only Standard | 10GB | 24 months | £8/mo | Email & light browsing |
| SIM Only Unlimited | Unlimited | 24 months | £10/mo Best Value | Heavy users & hotspotting |
| SIM Only 30-Day | Unlimited | 30 days | £14/mo | Flexible, no commitment |
| iPhone 16 + 25GB | 25GB | 24 months | £32/mo | Handset + data bundle |
| Samsung S25 + Unlimited | Unlimited | 24 months | £36/mo | Android power users |
All prices exclude VAT. VAT-registered businesses reclaim 20%. Annual RPI price increases apply.
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Compare Three DealsThree vs Other Networks on Price
Where Three really shines is on unlimited data pricing:
| Network | Unlimited SIM Only | Difference vs Three |
|---|---|---|
| Three | £10/mo Cheapest | — |
| Vodafone | £16/mo | +£6/mo (+£72/yr) |
| EE | £19/mo | +£9/mo (+£108/yr) |
| O2 | £25/mo | +£15/mo (+£180/yr) |
For a business with 10 unlimited data lines, choosing Three over O2 saves £1,800 per year before VAT. That’s a significant saving.
Where Three Falls Short
In the interest of honest comparison, Three isn’t perfect for every business:
- Rural coverage — Three’s 4G coverage in rural areas is weaker than EE and Vodafone. If your team works on remote sites, EE may be safer.
- Customer service — Three’s business support is not UK-based and wait times can be longer than EE or O2.
- 5G reach — while strong in cities, Three’s 5G is less widespread in suburban areas compared to EE.
For a detailed head-to-head, see our EE vs Three business mobile comparison.
Who Is Three Best For?
- Budget-conscious businesses that want the most data for the lowest price
- Urban-based teams who work primarily in towns and cities
- Data-heavy users who hotspot, stream, or use cloud apps extensively
- Startups and sole traders keeping overheads low
- Multi-line accounts where the per-line saving compounds significantly
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Get Your QuoteWhy is Three popular for business mobiles?
Three offers the UK’s cheapest unlimited data at £10/month SIM only. For businesses that need lots of data without high bills, Three delivers the best value of any major network.
How much are Three business mobile plans?
SIM only from £6/month (1GB) to £10/month (unlimited). Handset contracts from £28/month. All prices exclude VAT. 30-day rolling contracts available from £14/month.
Is Three’s coverage good enough for business?
In urban areas, Three’s coverage is excellent with strong 5G. In rural areas, it’s weaker than EE and Vodafone. Check coverage at your work locations before committing. We can advise on the best network for your area.
Does Three offer multi-line business discounts?
Yes. Volume discounts of 10-15% for 5+ lines. For 20+ lines, bespoke pricing is available through Compare The Networks.