Three vs O2 Business Mobile 2026 | Head-to-Head Comparison
Compare The Networks is an OFCOM regulated, independent comparison service helping UK businesses find the best telecoms deals since 2008. We compare Three vs O2 business mobile from EE, Vodafone, O2 and Three so you can make an informed decision.
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Three vs O2 for Business Mobile
Choosing between Three and O2 for your business mobiles comes down to coverage, pricing, and features. Here is how they compare in 2026.
| Feature | Three | O2 | |---------|---------|---------| | 4G Coverage | Check at your postcode | Check at your postcode | | 5G Availability | Expanding | Expanding | | SIM Only From | £6+VAT/month | £6+VAT/month | | Contract From | £11+VAT/month | £11+VAT/month | | Multi Line Discount | Yes (5+ lines) | Yes (5+ lines) | | Business Support | Dedicated account management | Dedicated account management |
The Coverage Question
Coverage is the single most important factor. The cheapest deal is worthless if you cannot make calls from your office. We check coverage for both Three and O2 at your exact postcodes before recommending either one.
Why Not Just Compare These Two?
Limiting yourself to Three and O2 means you might miss a better deal from the other two networks. We compare all four (EE, Vodafone, O2, Three) in one free quote so you can see the full picture.
Compare all four networks for your business
Frequently Asked Questions
Is Three or O2 better for unlimited data business plans?
Three offers the cheapest unlimited data business plans in the UK, making it the best value for data-heavy businesses. O2 also offers unlimited data plans but at a higher price point. If unlimited data at the lowest cost is your priority, Three is the clear winner.
Does O2 or Three have better EU roaming for business?
O2 is far superior for EU roaming. O2 business plans include Roam at Home with 25GB of EU data plus inclusive minutes and texts at no extra cost. Three charges for EU roaming on most business plans. If your team travels to Europe regularly, O2 is the better choice.
Which has better 5G — Three or O2?
Three has strong 5G coverage in major UK cities and holds significant 5G spectrum. O2's 5G is growing steadily but covers fewer locations. Three's merger with Vodafone will further boost its 5G capability. For city-based businesses, Three currently offers competitive 5G coverage.
What happens to Three business contracts after the Vodafone merger?
Existing Three business contracts will be honoured. The merged Vodafone-Three entity will create the UK's largest mobile network by mast count and spectrum holdings. Three business customers can expect improved coverage and capacity as the combined infrastructure rolls out.
Can I switch from Three to O2 or O2 to Three?
Yes. Request a PAC code from your current provider to port your number. The switch typically completes within one working day. Compare The Networks manages the process for free and pays agreed switching fees. Terms apply.