Business SIM Only Plans Compared: How to Choose the Right One (2026)

Prices are indicative, exclude VAT, and may depend on contract length, connection quantity and current promotional availability. Correct at the time of writing, June 2026.

Most businesses choose a SIM only plan on monthly price alone, and it is the wrong place to start. We typically see two expensive habits: teams that pick the cheapest SIM and then pay roaming charges the first week someone flies to a client, and teams that pick unlimited “to be safe” while actually using 30GB.

This guide compares the four major UK mobile networks across the six decisions that actually change the bill: data, coverage, roaming, contract length, support and team size. It includes current pricing, the best deals for £15 a month or less, and a realistic look at which network wins each scenario.

How Do I Choose a Business SIM Only Plan?

Six decisions settle it. Data allowance is the biggest cost lever, and the one most often got wrong. Coverage is whether your team gets signal where they actually work. Roaming is the same question abroad: the coverage and cost of using a phone in other countries. Contract length is really about how certain your business is, not just price. Support is the decision most buyers skip and later regret. And team size changes the structure entirely.

Teams with fewer than 10 employees usually choose an allowance for each line. Businesses with at least 10 employees and five connections may qualify for a shared data plan instead.

The rest of this guide takes each decision in turn. If you would rather get to an answer fast, start with the decision tree below.

Business SIM Only Plan Decision Tree

The tree below maps the whole thing top to bottom, from team size through to a specific plan. Use it for a quick answer, or carry on reading for the full comparison behind each step.

How Much Data Does My Team Actually Need?

Most teams need less than they think. We typically see people ask for unlimited and turn out to be using 20 to 30GB a month when they check. 50GB covers the large majority of business users comfortably.

Over-buying data is the single most common source of waste on a business mobile account. A simple way to place each person without anyone digging through phone settings:

• Light, up to 10GB a month. Mostly email, calls, messaging and light browsing. A desk-based worker on Wi-Fi most of the day.
• Standard, 10 to 50GB a month. Work apps, maps, photos and the occasional video call. Hybrid workers out of the office a few days a week.
• Heavy, 50GB and up. Frequent video calls, hotspotting a laptop, field work and large uploads. People who use mobile data as their main connection.

All prices per month, ex VAT.

Usage tier	Typical user	What it covers	Cheapest plan at this tier
Light (up to 10GB)	Office and Wi-Fi based	Email, calls, messaging, browsing, maps	O2 8GB, £7.80
Standard (10–50GB)	Hybrid, out a few days a week	Work apps, video calls, tethering, uploads	O2 50GB or EE 50GB, £12
Heavy (50GB+)	Field, remote, mobile first	Continuous video, tethering, large files	Three Unlimited, £15

If you want to sense-check what an allowance translates to in real use, our guide to mobile data usage breaks it down task by task. The short version: if you are consistently using less than half your allowance, you are on the wrong plan.

Not sure what your team really uses? A free bill analysis shows your actual usage against what you are paying.

Should I Buy Individual SIMs or Pool My Data?

Once you reach 10 employees, pooling the team’s data into one shared allowance can often reduce waste compared with choosing a separate allowance for every SIM.

A Smart Spend plan puts the whole team’s data in one pot, monitored and reviewed each quarter so the bill stays predictable. The heavier users draw from the allowance the lighter users never touch.

Here is why it matters. Buy direct, and the network sells each line its own allowance with nobody netting it off across the team. You can end up with ten people on 20GB each, half of them using 3GB, paying for headroom that never gets touched. Pool that same usage and you often need a fraction of the total.

There is a threshold: shared data plans need at least 5 connections and 10 employees. Below that, individual plans are the route.

Have 10 or more employees? Ask us to compare individual allowances against a pooled plan before you choose.

Business SIM Only Deals Compared by Network

Here is each major network at the data tiers most businesses buy, with the lowest current price per line per month, ex VAT, the contract term, and whether EU roaming is included. Where a network has no plan at exactly that size, the nearest within the same user tier is shown.

Network	Light (up to 10GB)	Mid data	Unlimited	EU roaming	Best known for
EE	10GB, £10, 36m	50GB, £12, 36m	£20, 36m	Add-on	Coverage and Wi-Fi calling
O2	8GB, £7.80, 24/36m	50GB, £12, 24/36m	£20, 24/36m	Included	Lowest cost, roaming across range
Three	25GB, £12, 24m	25GB, £12, 24m	£15, 24m	Day pass	Cheapest unlimited, worldwide passes
Vodafone	12GB, £17, 24m	25GB, £22.50, 36m	£24.50, 36m	Limited	Rural coverage and wide roaming

EE is often the strongest starting point for nationwide coverage, although results vary by postcode. Wi-Fi calling is standard across the range, and the six-month early upgrade keeps a cheap SIM only deal from trapping you if you later want a handset. It is rarely the cheapest, but at 50GB for £12 it is competitive where it counts.

O2 is the value pick and the broadest range. Plans start from £5.80 a line, and EU roaming is included across the range, even at entry level. Its keenest plans cover EU roaming for data and calls back to the UK. Pay a little more and O2 adds UK-to-EU minutes, international dialling and data rollover, so a heavier traveller can move up without leaving the network.

Three has the lowest-priced unlimited in this comparison at £15, and the cleanest worldwide travel option through Go Roam day passes, at £1.67 a day in Europe across 54 destinations and £4.17 a day across 23 worldwide destinations. Worth knowing: its EU roaming plans cap data at 12GB a month when you are abroad, even on unlimited.

Vodafone rarely wins on price, but it earns its place two ways. It can beat EE for coverage at specific rural sites, and its wider roaming range handles worldwide travel that other networks do not. It is the natural pick if you already run a Vodafone estate.

What Are the Best Business SIM Only Deals for £15 a Month or Less?

If your priority is a low per-line cost for a small UK team, every major network has an option costing £15 a month or less, but the value is not evenly spread. Here are the standout picks by budget, all per month, ex VAT.

Pick	Plan	Term	Price/line	Important limitation	Link
Best under £10	O2 8GB	24/36m	£7.80	Light use only	View deal
Best around £12	EE 50GB or O2 50GB	36m / 24–36m	£12	EE no roaming; O2 entry roaming only	View deals
Best high-data for £15 or less	O2 100GB	24/36m	£13	Entry roaming only	View deals
Best unlimited for £15 or less	Three Unlimited	24m	£15	UK only, weaker rural coverage	View deal

The best option: pick the cheapest plan that fits, not the cheapest plan full stop. O2 is currently the lowest-priced option in this comparison, from £5.80, and still includes EU roaming. For most small teams the value sweet spot is 50GB at £12, on either EE or O2.

The £15 ceiling only starts to cost you something real when you need UK-to-EU calling, unlimited data with roaming, or stronger coverage at specific rural sites.

The full tariff table for every plan costing £15 a month or less sits below for reference.

Plan	Data	Term	Network	Price/line	Link
O2 1GB	1GB	36m	O2	£5.80	View deal
O2 5GB	5GB	24/36m	O2	£7.50	View deal
O2 8GB	8GB	24/36m	O2	£7.80	View deal
O2 16GB	16GB	24/36m	O2	£9	View deal
EE 10GB	10GB	36m	EE	£10	View deal
O2 30GB	30GB	24/36m	O2	£11	View deal
Vodafone 2GB	2GB	24m	Vodafone	£11	View deal
EE 50GB	50GB	36m	EE	£12	View deal
O2 50GB	50GB	24/36m	O2	£12	View deal
Three 25GB	25GB	24m	Three	£12	View deal
O2 100GB	100GB	24/36m	O2	£13	View deals
Vodafone 6GB	6GB	24m	Vodafone	£14	View deal
EE 100GB	100GB	36m	EE	£14	View deal
Three Unlimited	Unlimited	24m	Three	£15	View deal

Which Network Is Best for Coverage?

There is no single winner, and any guide that tells you otherwise has not checked a postcode. EE is often the strongest starting point for nationwide coverage, although results vary by location. We typically see Vodafone beat it at specific rural sites, and some businesses choose Vodafone deliberately for that reason.

Network	Urban	Rural	Indoor / Wi-Fi calling
EE	Strongest	Strong, often best	Wi-Fi calling standard
Vodafone	Strong	Can beat EE at specific sites	Wi-Fi calling available
O2	Solid	Patchier	Good in thick-walled buildings
Three	Good, much improved	Weakest of the four	Tethering up to allowance

Because coverage is location-specific, the step that prevents the most disruption is checking your sites before you commit, not after. We check coverage at a business’s actual postcodes as the first step, which immediately rules out any network that will not work where your people are.

It is also why putting different users on the network that covers their workspace best can outperform forcing everyone onto one network, while still being managed as one account.

Not sure which network covers your sites? We can compare EE, O2, Vodafone and Three at your postcodes.

Which Network Is Best for Travel and Roaming?

Once your team leaves the UK, the question becomes coverage abroad: roaming is simply whether their phone works in other countries, and what it costs. It is where the networks differ most, and where a cheap SIM becomes a false economy the moment someone lands overseas. It is also the area competitors gloss over, so here it is in full. All roaming terms below are per the plans we currently hold.

Network	EU roaming	Worldwide	UK-to-EU calling / IDD	Data cap when roaming
EE	Via All Rounder add-on	Add-on, destinations vary	Yes, on All Rounder	Per plan
O2	Included across the range	No	On higher-tier plans	Standard allowance
Three	£1.67/day, 54 destinations	£4.17/day, 23 destinations	Limited	12GB when roaming
Vodafone	ROI, Isle of Man, Norway, Iceland only	Via wider roaming range	Via add-on	Per plan

For regular EU travel, O2 is the cleanest answer. EU roaming is included on every plan, and the higher tiers add UK-to-EU minutes and international dialling for someone who works while they travel. If cost matters more than calling, O2’s entry plans include EU roaming from £7.50.

Three’s day-pass model suits travel you can predict, and its unlimited plan with EU and worldwide roaming built in runs £34.33 a line for someone who travels widely and often.

For worldwide travel, this is a conversation rather than a plan you pick off a table. The detail most buyers miss, and the one that causes unexpected bills, is that on some worldwide roaming plans you can only call back to the UK, while calling within the country you are visiting is charged separately and at a higher rate.

Team travelling beyond the EU? Tell us where and how often, and we will work out the roaming tariff that avoids the surprises.

Which Networks Offer the Best Account Management and Support?

Support quality often depends less on the network itself and more on how the account is managed. One of the most common reasons businesses come to us is frustration with long waits, changing contacts and issues being passed between teams.

A real example we see often: a customer with two SIMs on a network, trying to get a simple PDF bill so they could add another line, going back and forth for weeks because no one took ownership. When dealing directly with a large network, customers may speak to a different agent each time and need to repeat the background to an issue. Through a specialist, the account can be managed by a named contact who already understands the business and takes ownership of the next step.

Factor	Direct to network	Specialist managed
Point of contact	May vary between interactions	Named contact who knows your account
Issue ownership	Follow up through different teams	Managed through one point of contact
Billing and admin	Portal or central support team	Hands-on billing and account support
Adding or changing lines	Network’s standard channels	Coordinated through the same account team

This is where buying through a specialist earns its keep. We have managed UK business mobile accounts since 1999, and a single point of contact means an issue gets owned rather than passed around. If account management is the thing your current setup is failing on, it is the clearest reason to move, whichever network you land on.

Should I Choose a 30-Day, 12-Month, 24-Month or 36-Month SIM Contract?

Contract length is a certainty question. The longer you commit, the lower the rate usually goes, but only if your headcount and usage are stable enough to commit.

Term	Price position	Flexibility	Suits
30-day rolling	Highest	Cancel anytime, 30 days’ notice	Contractors, seasonal, trying a network
12-month	Slight premium	Annual reset	Unsure on network or data needs
24-month	Low	EE: move to a handset plan after 4 months	Most businesses
36-month	Usually lowest	Locked in	Stable teams

Two caveats: First, 36 months is not always cheaper: Vodafone’s 36-month 2GB at £13.50 is dearer than its 24-month 2GB at £11, so check the specific plan.

Second, if you are mid-contract on existing SIMs, the early termination cost has to be weighed against the saving before any of this applies. We typically see customers assume they are stuck when a review shows that moving, even with a buyout, leaves them ahead.

Common Mistakes Businesses Make

• Buying data on a guess. Over-speccing to unlimited “to be safe” is the most expensive habit. Most people on unlimited use 20 to 30GB.
• Picking the cheapest SIM for a team that travels. A no-roaming plan can generate unexpected charges the first time someone lands abroad.
• Defaulting to the network you already use. The best coverage and price at your current sites may not be the network that suited you three years ago.
• Giving every SIM its own allowance when you have 10 or more employees. Pooled data can often reduce waste by letting heavier users draw from data that lighter users do not need.
• Auto-renewing on an expired contract. Past your initial term and paying the same rate, you are paying for nothing extra. It is the quickest saving available.

How Do I Switch and Keep My Number?

Switching is simpler than most businesses expect, and you can normally keep your existing number. Text PAC to 65075 from the phone to receive your porting code free of charge, then give it to your new provider.

Once submitted, the number will usually transfer within one working day, although larger or more complex business ports can take longer. The service linked to that number normally closes when the port completes, but you should still check for any remaining lines, notice periods or early termination charges. If you move through us, we manage the porting process and setup for you.

Get a Tailored Business SIM Only Recommendation

If you have worked through the six decisions, you should have a data tier, a network, a contract length and a rough plan in mind. The fastest way to be sure is to pressure-test it against your real usage and coverage.

Tell us your team size, typical data use and main work locations. We will compare suitable plans across the major networks, check coverage, and explain the contract and roaming differences before you choose. We are an independent business mobile specialist working across EE, O2, Vodafone and Three, so the recommendation follows your team rather than one network’s pitch.

Talk to an expert or build it yourself with our mobile plan builder.