SIM only business contracts are the smartest way to get business-grade mobile service without paying for a handset you don’t need. If your team already has phones — or you’re happy buying handsets outright — a SIM-only deal saves 40–60% compared to a traditional contract.
In 2026, business SIM-only plans start from just £6/month with proper VAT invoicing, multi-line management, and access to all four major UK networks.
Why SIM Only Makes Sense for Business
- Lower monthly costs — you’re only paying for airtime, not a phone
- Shorter commitments — many plans offer 30-day rolling contracts
- Flexibility to scale — add or remove lines as your team changes
- Full VAT recovery — same tax benefits as any business contract
- Use existing phones — no waste, no unnecessary upgrades
Best SIM Only Business Deals by Network
| Network | From | Data | Contract | Key Feature |
|---|---|---|---|---|
| EE | £7.20/mo | 5GB–Unlimited | 12 or 24 months | Best 5G coverage + BT WiFi |
| O2 | £6.50/mo | 1GB–Unlimited | 12 or 24 months | Multi-line fleet pricing |
| Three | £6.00/mo | 5GB–Unlimited | 24 months | Cheapest unlimited data |
| Vodafone | £7.00/mo | 5GB–Unlimited | 12 or 24 months | Bundle with broadband for extra savings |
SIM Only vs Handset Contract: Which Is Better?
It depends on your situation:
| Factor | SIM Only | Handset Contract |
|---|---|---|
| Monthly cost | £6–15 | £20–40 |
| Flexibility | 30-day available | 24–36 months locked |
| New phone included | No | Yes |
| Best for | Teams with existing phones | Teams needing new devices |
Understanding SIM Only Contract Terms
Business SIM-only contracts come in several flavours. Understanding the differences helps you pick the right one:
30-Day Rolling Contracts
Maximum flexibility — cancel with just 30 days’ notice. The monthly cost is typically 10–15% higher than a 12-month contract, but you’re never locked in. Ideal for startups with unpredictable headcount, temporary staff, or businesses testing a new network before committing long-term.
12-Month Contracts
The most popular choice for small businesses. Good balance of price and commitment. You get better rates than 30-day rolling, but you’re not locked in for two years. At the end of the 12 months, you can switch network, upgrade, or move to rolling monthly.
24-Month Contracts
The cheapest per-month option. Best for established businesses with stable team sizes. The downside is reduced flexibility — if you need to reduce lines mid-contract, early exit fees may apply. However, most providers allow you to add lines at any time at the same rate.
Data Allowances: How Much Does Your Business Actually Need?
One of the most common mistakes businesses make is over-buying data. Here’s a realistic guide to data usage by work type:
| Activity | Data Usage | Notes |
|---|---|---|
| Email (text only) | ~50MB/month | Negligible even with heavy email use |
| Email with attachments | 200–500MB/month | Depends on attachment sizes |
| Web browsing | 100–300MB/month | Most pages are 2–5MB each |
| Microsoft Teams/Zoom calls | 1–2GB/month | ~800MB per hour of video calling |
| Cloud apps (CRM, Office 365) | 500MB–1GB/month | Varies by app and usage intensity |
| Mobile hotspot (laptop tethering) | 5–15GB/month | Heaviest data user — equivalent to broadband use |
| GPS/Maps navigation | 50–100MB/month | Very light — maps are pre-cached |
Recommended Allowances by Role
- Office-based (on WiFi most of the time): 5GB is plenty. You’re mainly using mobile data during commutes and breaks.
- Hybrid workers: 10–15GB. Covers occasional hotspot use and video calls when not on WiFi.
- Field workers and sales: 20–30GB. Regular hotspot use, CRM access, navigation, and video calls from client sites.
- Heavy users and directors: Unlimited. Removes any worry about overages and typically costs only £3–5/month more than a 30GB plan.
Multi-SIM Discounts: Where the Real Savings Are
Individual SIM-only prices from network websites are the consumer retail rate. Business SIM contracts with multiple lines unlock wholesale pricing that’s significantly cheaper:
| Number of Lines | Typical Discount | Example (10GB SIM, was £10/mo) |
|---|---|---|
| 1–2 lines | Standard rate | £10.00/mo per line |
| 3–5 lines | 5–10% off | £9.00–9.50/mo per line |
| 5–10 lines | 10–15% off | £8.50–9.00/mo per line |
| 10–25 lines | 15–20% off | £8.00–8.50/mo per line |
| 25+ lines | 20–30% off | £7.00–8.00/mo per line |
These discounts are negotiated, not published. Going direct to the network’s website won’t show you these rates — you need to speak to a business sales team or, better still, an independent broker who negotiates across all four networks.
SIM Only with eSIM: The Future of Business Mobiles
An increasingly popular option is eSIM for business. Instead of a physical SIM card, your provider activates the plan digitally on your phone. Benefits include:
- Instant activation: No waiting for a SIM in the post — the plan is active within minutes
- Dual SIM capability: Use the eSIM for business and a physical SIM for personal — two numbers on one phone
- Easy switching: Swapping between plans or networks is simpler with eSIM
- No SIM card to lose: Useful for field workers and teams in challenging environments
All four major networks now support eSIM for business accounts, and most phones from 2022 onwards are eSIM-compatible (iPhone 14+, Samsung S22+, Google Pixel 6+).
Keeping Your Existing Numbers: The PAC Code Process
Switching to a new SIM-only business contract doesn’t mean losing your phone numbers. The PAC code process transfers your existing number to the new provider:
- Request your PAC code: Text PAC to 65075 from each phone. You’ll receive the code by SMS within minutes.
- Give the PAC to your new provider: They submit it during activation.
- Number ports within 1 working day: There’s typically a 2–4 hour window where the old SIM stops working and the new SIM takes over.
- Old contract auto-cancels: Once the PAC is used, your previous contract is automatically terminated. No need to call and cancel separately.
How to Switch to SIM Only
- Request a PAC code from your current provider
- Choose a business SIM-only plan
- Activate the new SIM and port your number (takes 1 working day)
- Start saving immediately
Get a free SIM-only business quote and see how much your team could save — takes 60 seconds.
Business SIM Only vs Consumer SIM Only: The Real Difference
On the surface, a £10/month business SIM-only plan and a £10/month consumer SIM-only plan look identical. But the differences are significant for anyone running a business:
Financial Differences
- VAT recovery: Business invoices include VAT breakdowns, letting you reclaim 20%. A £10/mo plan effectively costs £8.33/mo. Consumer invoices don’t support this.
- Multi-line pricing: Order 5+ business SIMs and per-line costs drop 10–15%. Consumer plans are always per-individual, no discounts.
- Corporation Tax: The full cost reduces your taxable profit, saving an additional 25% for limited companies.
Management Differences
- Single consolidated invoice: One bill for all lines, broken down per employee. No chasing individual receipts.
- Spend caps and controls: Set data limits, block premium numbers, and prevent bill shock per line.
- Online management portal: Add lines, swap plans, and view real-time usage without calling anyone.
- Named account manager: One person who knows your setup and handles everything.
Support Differences
- Business support hours: Extended hours, often 7am–9pm, with dedicated business teams.
- Priority issue resolution: Network faults and SIM replacements handled faster than consumer tickets.
- Proactive renewal management: Good providers contact you before contracts expire with fresh quotes, preventing expensive auto-renewals.
Frequently Asked Questions
Can I use a business SIM in any unlocked phone?
Yes. A business SIM works in any unlocked phone, just like a consumer SIM. If your phone is still locked to a previous network, you can request an unlock code (free if your contract has ended) or your new provider can help arrange this.
What if I don’t use all my data?
Unlike some consumer plans, most business SIM contracts don’t roll over unused data. This is why it’s important to right-size your plan. If you’re consistently using less than half your allowance, ask your provider to move you to a lower tier at your next renewal — or consider a shared data pool for your team.
Can I keep my number when switching to a business SIM?
Absolutely. The PAC code process transfers your existing number to the new business SIM. Your contacts, clients, and marketing materials all keep working with the same number. The transfer takes one working day.
Is 5G available on business SIM-only plans?
Yes — all four major networks include 5G at no extra cost on most business plans. As long as your phone supports 5G and you’re in a 5G coverage area, you’ll automatically connect to the faster network. Check 5G coverage at your locations before choosing a network.
Do I need a different SIM for each network?
Yes — each network uses its own SIM card. When you switch from one network to another, you’ll receive new SIM cards (or eSIM activations) from the new provider. Your existing phone numbers transfer across using PAC codes, so your contacts and clients won’t notice any change. The swap process is seamless: insert the new SIM, your number ports within 24 hours, and you’re up and running on the new network with no downtime to speak of.
Related Guides
Related Reading
More from the Connection Technologies blog.
Gina is a Business Development Executive at Connection Technologies, helping SMEs find the right mobile and connectivity solutions for their needs.