Business SIM only deals are the most cost-effective way to get your team connected. No handset cost, shorter contracts, and the lowest monthly outlay of any business mobile option. In 2026, business SIM deals start from just £6/month — dropping to £5 after VAT recovery.
This guide compares every business SIM only deal from the four major UK networks, explains which data tier suits different roles, and shows you how to get below published prices through volume discounts and broker negotiation.
Business SIM Only Deals: Full Network Comparison
5GB SIM Deals (Light Users)
| Network | Price | After VAT | 5G | Contract | EU Roaming |
|---|---|---|---|---|---|
| Three | £6/mo | £5.00 | Yes | 24 months | £2/day |
| O2 | £7/mo | £5.83 | Yes | 24 months | Included |
| Vodafone | £7/mo | £5.83 | Yes | 24 months | Included |
| EE | £7.20/mo | £6.00 | Yes | 24 months | Included |
15GB SIM Deals (Regular Users)
| Network | Price | After VAT |
|---|---|---|
| Three | £8/mo | £6.67 |
| O2 | £9/mo | £7.50 |
| Vodafone | £9.50/mo | £7.92 |
| EE | £10/mo | £8.33 |
Unlimited SIM Deals (Heavy Users)
| Network | Price | After VAT | Tethering Cap |
|---|---|---|---|
| Three | £12/mo | £10.00 | 30GB |
| O2 | £14/mo | £11.67 | 50GB |
| Vodafone | £15/mo | £12.50 | 80GB |
| EE | £16/mo | £13.33 | Unlimited |
Which Data Tier Do You Need?
- 5GB: Office workers primarily on WiFi. Email, messaging, light browsing on commute. Cost: £5–6/mo after VAT
- 10–15GB: Mixed office/field workers. Client visits, maps, CRM access, occasional video calls. Cost: £6.67–8.33/mo after VAT
- 25–50GB: Regular field workers. Frequent tethering, video calls, large file uploads. Cost: £8–11/mo after VAT
- Unlimited: Heavy mobile workers. Primary internet via mobile, constant tethering, streaming. Cost: £10–13.33/mo after VAT
Why Business SIM Only Is the Smart Default
For any employee who already has a working phone, SIM only is the obvious choice:
- 60–70% cheaper than handset contracts (£6–12/mo vs £18–35/mo)
- Shorter commitment: 12-month or 30-day rolling vs 24-month handset contracts
- Faster to deploy: SIM arrives next day, pop it in, done. No phone procurement, no device setup
- Maximum flexibility: Easier to change plans, switch networks, or cancel for staff who leave
Getting Below Published Prices
Volume Discounts
Order 3+ SIMs together for 10–15% off. 10+ SIMs: 15–20% off. 25+: 20–30% off. Three’s £6/mo becomes as low as £4.20/mo with maximum volume discount — £3.50/mo after VAT.
Broker Negotiation
Independent brokers access wholesale pricing from all four networks. Even for small orders (3–5 SIMs), broker prices are typically £1–2/month cheaper per line than direct. The service is free — the winning network pays the broker.
Contract Length Trade-Offs
24-month: lowest per-month price. 12-month: £1–2/mo more but renegotiate sooner. 30-day rolling: £2–4/mo more but maximum flexibility.
Get a free business SIM only comparison — 60 seconds, all networks, broker-negotiated rates
SIM Only vs PAYG: Which Is Better for Business?
Pay-as-you-go might seem low-risk because there is no contract, but the per-minute and per-megabyte costs are dramatically higher than a SIM only plan. A typical PAYG rate of 10p per minute and 1p per MB means a moderate user spending 60 minutes on calls and consuming 5 GB of data would pay roughly £55 per month. The same usage on a business SIM only contract costs £6 to £8 per month. The only scenario where PAYG makes financial sense is for a phone that is used once or twice a month — a backup device in a locked drawer, for instance.
Business SIM only plans also come with VAT invoicing, centralised billing, and spend management tools. None of those features exist on consumer PAYG. If you need to track costs across a team, PAYG creates an administrative headache because each top-up is a separate transaction with no consolidated reporting. With a business SIM only contract, every line appears on a single monthly invoice that feeds directly into your accounts software.
How to Audit Your Current SIM Usage and Right-Size Plans
Most businesses are paying for data their teams never use. The average UK business mobile user consumes 4.2 GB per month, yet many are on 20 GB or unlimited plans because nobody has checked actual usage. Here is a practical audit process you can complete in under an hour.
First, request itemised billing from your current provider. Every network provides this through their business portal, usually as a downloadable CSV. Export the last three months. Second, sort each line by data consumption. You are looking for the 90th-percentile usage — the month where each person used the most data. That is the number you should plan around, not the average, because you want headroom for busy months without paying for capacity you will never touch.
Third, group your lines into tiers. Staff consistently below 3 GB belong on a 5 GB plan. Staff between 3 and 10 GB belong on 10 to 15 GB. Anyone regularly over 15 GB should be on unlimited. This simple exercise typically identifies 30 to 40 per cent of lines that can drop to a lower tier, saving £2 to £5 per line per month. On a 20-line account that is up to £100 per month or £1,200 per year. You can use your provider’s spend management portal to set alerts at 80 per cent of each allocation so you catch changes before overage charges hit.
eSIM for Business Explained
An eSIM is a digital SIM embedded inside a phone that is programmed remotely instead of requiring a physical card. Every flagship phone released since 2022 supports eSIM, and many mid-range devices now include it too. For businesses, eSIM offers three practical advantages over traditional SIMs.
Deployment speed is the most obvious benefit. Instead of waiting for SIM cards to arrive by post, an eSIM can be activated within minutes by scanning a QR code or receiving an activation link. If a new starter joins on Monday morning, their line can be live before their first coffee. This is transformative for businesses with multiple sites or remote workers who cannot easily visit an office to collect a physical SIM.
The second advantage is dual-SIM capability. An eSIM and a physical SIM can run simultaneously on the same device, giving each phone two numbers and two data connections. A common use case is keeping a personal SIM alongside a business eSIM on a single handset, which simplifies BYOD policies and eliminates the need to carry two phones. The third advantage is security. Because the eSIM cannot be physically removed, it reduces the risk of SIM-swap attacks and means a lost phone can still be tracked and wiped remotely even if someone ejects the SIM tray.
Managing SIM Deployment Across a Team
Rolling out SIM only plans across 10 or more employees requires a bit of project management. Start by creating a simple spreadsheet listing every person who needs a SIM, their current number if porting, the data tier you have chosen for them, and the target activation date. Share this with your provider or broker so they can prepare all SIMs in a single batch order.
Number porting is the step that catches most businesses off guard. Each existing number requires a PAC code from the old network, and all PAC codes should be requested on the same day so the ports happen simultaneously. If you stagger them over a week, you end up with half the team on old SIMs and half on new ones, which complicates billing and support. Most providers can coordinate a bulk port where all numbers switch at 6 PM on a chosen date, giving you a clean cutover.
Once the SIMs are active, configure mobile device management if you use it, set up spend caps, and send each employee a one-page setup guide. The whole process, from placing the order to having every line live, typically takes five working days for up to 50 lines.
Real-World Cost Scenarios for 5, 10, and 20 Lines
To make the savings tangible, here are three worked examples based on typical 2026 pricing from a broker-negotiated deal.
Five-line team (small office): Three staff on 5 GB at £5.50 per month and two on 15 GB at £7.50 per month. Monthly total: £31.50 before VAT, £26.25 after VAT recovery. Annual cost: £315. Compare this to five consumer contracts averaging £22 per month each: £1,320 per year. Annual saving: over £1,000.
Ten-line team (growing SME): Five lines on 5 GB at £5 per month, three on 15 GB at £7 per month, and two on unlimited at £10 per month. Monthly total: £66 before VAT, £55 after VAT recovery, with an additional 15 per cent volume discount bringing the effective cost to £46.75. Annual cost: £561. The equivalent handset contracts for 10 users would run to approximately £3,000 per year, so the saving exceeds £2,400. Review our best business mobile plans guide for current rates across all tiers.
Twenty-line team (established business): Ten lines on 5 GB, six on 15 GB, and four on unlimited. With 20-plus volume discount of 20 per cent, the monthly cost drops to around £80 after VAT recovery. Annual cost: roughly £960. Twenty handset contracts at an average of £25 per month would cost £6,000 per year. The SIM only approach saves over £5,000 annually — enough to fund a company away day or reinvest in new equipment. If any of these lines also need EE coverage for rural locations, the premium is only £1 to £2 per line more, which barely dents the overall saving.
Frequently Asked Questions
Can I keep my existing phone numbers on business SIM only?
Yes — transfer any UK number via PAC code within 24 hours. Free, handled by your new provider.
Are business SIM only deals available for just one line?
Yes — all four networks offer business SIM contracts from a single line. You still get VAT invoicing, business billing, and dedicated support even on one SIM.
What if I need to add handset contracts later?
Business accounts can mix SIM only and handset contracts on the same invoice. Adding handset lines later doesn’t affect your existing SIM only deals.
Do business SIM only deals include 5G?
Yes — all four networks include 5G on business SIM plans at no extra cost. You’ll automatically connect to 5G where available.
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