Skip to Search Skip to Content Skip to Footer

Order by phone: 0808 258 0333

We're here until 8pm today: Speak to our sales team

We're here until 5pm today: Speak to our sales team

Boundless multi-line SIM plans

More unlimited SIMs for less

  • Unlock exclusive business class roaming discounts on 24 month plans
  • Get up to 50 business SIMs on The UK's Fastest 5G Network [3]
  • The more SIMs you buy, the more you save, even when adding more later
Three Business Boundless multi-line SIM plan with unlimited data and flexible roaming options.

More unlimited SIMs for less

  • Unlock exclusive business class roaming discounts on 24 month plans
  • Get up to 50 business SIMs on The UK's Fastest 5G Network [3]
  • The more SIMs you buy, the more you save, even when adding more later
Three Business Boundless multi-line SIM plan with unlimited data and flexible roaming options.

Choose your contract length

24 month plans

For maximum savings, choose 20+ SIMs

Find your business SIM plan: cost calculator

Enter the number of SIMs you need, with or without roaming options, and we'll calculate your Monthly Cost on a 24 month plan.

Find your business SIM plan: cost calculator

Enter the number of SIMs you need, with or without roaming options, and we'll calculate your Monthly Cost on a 24 month plan.

24 month plans (with Go Roam in Europe)

24 month plans (with Go Roam Around the World)

Back to top

12 month plans

For maximum savings, choose 20+ SIMs

Back to top

Not a business owner, and not self-employed? Shop SIM for Personal

Why choose a Boundless SIM plan?

Empower your growing business with cost-saving SIM plans designed for flexibility and scalability

Connect abroad for less

Choose SIMs with inclusive business class roaming, and roam in the EU or around the world for less. [2]

5G SIMs

Choose physical SIMs or eSIMs, depending on your devices.

Big value for your business

The more you need, the less you pay per SIM, even when you buy over time. Choose SIMs with or without roaming.

Unlimited UK data, calls, texts

So your whole team can stay online and in touch, wherever they're working from.

Hassle-free switching

Enjoy a seamless transition to Three Business, without disruption to your team.

Dedicated business support

Our expert team are here to support you at every step, whatever you need.

Multi-SIM savings for businesses – the more you add, the more you save.

Do business abroad for less

With a 24 month Boundless plan, you can unlock exclusive roaming discounts. Choose SIMs with inclusive roaming - only the SIMs that need it - and pay less when you work in the EU or around the world.  [2]

Do business abroad for less

With a 24 month Boundless plan, you can unlock exclusive roaming discounts. Choose SIMs with inclusive roaming - only the SIMs that need it - and pay less when you work in the EU or around the world.  [2]

Talk to our business experts

The Big Network for your business

New to Three Business? Use our coverage checker below to see if you can access The UK's Fastest 5G Network [3].

Check coverage in your area

Here's what our customers say

3RiO

Malachy Lynn, Managing Director of 3RiO, tells The Telegraph how upgrading to fast 5G-powered technology has radically changed the way the company works, saving months of time spent on the road and processing video.

Malachy Lynn, Managing Director of 3RiO

Read more about how 5G technology has empowered 3RiO

West Atlantic

“It's essential that we have coverage everywhere we go. We often had to deal with companies delivering information on paper in airports we didn't know.  Now we can just get that information ourselves, wherever we are in the world, thanks to Three Business.”

Matthew Moran, Senior First Officer on a Boeing 737

How 5G connectivity ensures cargo airline West Atlantic delivers on time 

How secure is your business?

Every 19 seconds a small business in the UK is successfully hacked.[4]

45% of medium-sized businesses in the UK have experienced cyber crime in the last 12 months. [5]

Only 23% of businesses believe they are adequately protected. [6]

Don’t fall victim to cybercrime

Here's how Three Mobile Protect can keep your business safe, secure, and compliant. Get robust on-device protection, without compromising employee privacy.

More with Three Business

FAQs

Anyone with their own business age 18 and over (including sole traders) is eligible for a Boundless plan, and can get up to 50 unlimited business SIMs.

Boundless SIMs come with unlimited UK data, calls, and texts, and offer you the benefit of multi-line discounts. So the more you need, the less you pay per SIM, up to 50 SIMs. Choose SIMs with inclusive roaming in Europe and around the world (fair use policies apply  [2]), or a combination of SIMs with and without roaming – you’ll still get the Boundless discount. 

Yes, you can bring your number or numbers to Three Business via a hassle-free switching process. See our Bring your number to Three Business page for all the details.

The easiest way to pay your bill is by Direct Debit, which also saves you £5 a month. There are also other ways to pay, including via credit card, debit card or bank transfer. See our Ways to pay your bill page for all the information you need.

Yes, you get the benefit of the multi-line discount even when you buy SIMs over time, as well as when you combine SIMs with and without roaming. You can find all the details on our Boundless terms page.

Why choose Three Business?

More about our network

According to Ookla, our 5G's the fastest around. [3]

Terms and Conditions

Boundless Business Offer is available to business customers who are purchasing or upgrading to Three Business 12 and 24 month Unlimited SIM-only plans. Participants who purchase Unlimited SIMs on a 12 or 24 month plan from Three (whether purchase is made in-store, online, or by telephone via our contact centre) on or after 1 May 2021 are eligible to unlock a discounted price based on the number of 12 or 24 month Unlimited SIMS (as applicable) already in existence at the time of purchase and the number of additional 12 or 24 month Unlimited SIMs (as applicable) the customer wishes to purchase. 

Prices vary between 12 and 24 month plans. Boundless Business Offer not available in conjunction with any other offer. See full terms for details: Terms & Conditions | Three.

  • Annual Price Increase

    All Charges exclude VAT.  From Customer’s bill date each April, the Monthly Charge will increase by a fixed amount depending on the plan’s original Monthly Charge. Plans with an original Monthly Charge of £9.99 or less will increase by £0.50 per month. Plans from £10 to £20 will increase by £0.75 per month. Plans from £20.01 will increase by £1.50 per month. All Business Broadband Plans will increase by £1.60 per month. All increases exclude VAT. Excludes Three Business Adapt. See Adapt Plan information for annual price increases. Visit the price increase page for full details. 

    Three’s systems work to very small fractions, and each charge is rounded up or down to make it easier to read. This means that there may be a small inconsistency to the price shown in the shopping basket, compared to the statement which shows the price rise that will apply during the Minimum Term of the Plan and Customer’s bill, which both show the actual amount Customer will be charged. For more information, please see Three’s help and support pages or the Price Guide. The Plan’s Monthly Charge includes a £5 discount for paying by a recurring method, such as Direct Debit. The £5 monthly recurring payment discount and the annual price increase do not apply to Add-ons or Outside-of-Allowance Services. See Terms & Conditions | Three.

    Return to reference

  • Go Roam

    Go Roam on Boundless plans: £2 daily roaming charge waived for Go Roam in Europe destinations and £5 daily roaming charge waived in Go Roam Around the World destinations. This includes VAT where applicable and is per SIM. Republic of Ireland and Isle of Man are excluded from the daily charge. Fair use policies apply.

    Fair Use Policies apply.

    Go Roam in Europe - up to 12GB data, and use your UK monthly plan allowance for calls and texts back to the UK, or within Go Roam in Europe destinations.

    Go Roam Around the World - up to 12GB data, 3,000 minutes, and 5,000 texts per billing month. 

    If customers exceed these allowances, surcharges may be applied.

    If during any 4-month period, Customers roam in Go Roam destinations for 60 days or more, additional roaming charges may apply. Customers shall be notified before charges are applied.

    Return to reference

  • Ookla Speedtest

    Based on analysis by Ookla® of Speedtest Intelligence® data for Q1-Q2 2024. Ookla trademarks used under license and reprinted with permission.

    Return to reference

  • Hiscox Insurance

    Hiscox Insurance 2021 Cyber Report.

    Return to reference

  • UK Government Survey

    UK Gov Cyber Security Breaches Survey 2024

    Return to reference

  • Research Report

    Based on analysis from Three Business Medium Outlook Research Report 2024.

    Return to reference