Compare Cheap SIM-Only Deals and Save Today

Looking for cheap SIM-only deals? Our mobile SIM-only comparison tool helps you compare plans from leading UK networks in minutes.
A SIM-only contract lets you keep your current phone while switching networks, helping reduce your monthly cost without paying for a handset.
We compare the latest SIM-only offers from the UK’s top mobile networks, helping you quickly find the perfect plan based on price, data allowance, and contract length.
Deals and prices correct at time of publication. We may earn commission from affiliated products, which affects the table’s sort order.
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Chattr Unlimited

Exclusive Deal
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texts Unlimited
Minutes Unlimited
Data Unlimited
Contract 1 month
Monthly cost £20 /mth
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Uses O2's network No contracts and free delivery No annual price rises Roam freely in 43 European destinations Exclusive benefits and rewards

Chattr 50GB

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texts Unlimited
Minutes Unlimited
Data 50GB
Contract 1 month
Monthly cost £15 /mth
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Uses O2's network No contracts and free delivery No annual price rises Roam freely in 43 European destinations Exclusive benefits and rewards

Chattr 25GB

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texts Unlimited
Minutes Unlimited
Data 25GB
Contract 1 month
Monthly cost £14 /mth
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Uses O2's network No contracts and free delivery No annual price rises Roam freely in 43 European destinations Exclusive benefits and rewards

Chattr 5GB

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texts Unlimited
Minutes Unlimited
Data 5GB
Contract 1 month
Monthly cost £10 /mth
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Uses O2's network No contracts and free delivery No annual price rises Roam freely in 43 European destinations Exclusive benefits and rewards

Lebara Unlimited

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texts Unlimited
Minutes Unlimited
Data Unlimited
Contract 30-day rolling plan
Monthly cost £25 /mth
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No Annual Price Rises Use your plan in the EU or India at no extra cost Runs on Vodafone network No credit checks 100 International Minutes

O2 SIM Only on Classic - 24 Month contract

Unlimited mins & texts. Unlimited 5G data.

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texts Unlimited
Minutes Unlimited
Data Unlimited
Contract 24 Months
Monthly cost £32 /mth
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Get Unlimited data Roam freely in the EU Exclusive benefits and rewards O2 Priority Upgrade options after 3 months

Offer and pricing correct at time of publish.

O2 SIM Only on Classic

12 Month contract. Unlimited mins & texts. Unlimited 5G data

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texts Unlimited
Minutes Unlimited
Data Unlimited
Contract 12 Month Rolling Airtime Plan
Monthly cost £35 /mth
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Get Unlimited data Roam freely in the EU Boost your package with Extras One Extra included in this package O2 Priority

O2 SIM Only on Plus Unlimited

12 Month contract. Unlimited mins & texts. Unlimited 5G data

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texts Unlimited
Minutes Unlimited
Data Unlimited
Contract 12 Month Rolling Airtime Plan
Monthly cost £36.99 /mth
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Get Unlimited data Roam at no extra cost in 75 destinations worldwide Including the EU, the USA, Australia and Mexico Boost your package with Extras O2 Priority

Grade Mobile Unlimited

Change your plan anytime. No credit checks

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texts Unlimited
Minutes Unlimited
Data Unlimited
Contract Monthly
Monthly cost £25 /mth
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Unlimited UK calls and texts Uncapped speeds Keep your number 5G included Free delivery of SIM

1p Mobile 4GB

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texts Unlimited
Minutes Unlimited
Data 4GB
Contract 30-day rolling plan
Monthly cost £6 /mth
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UK's best coverage on 2G, 4G & 5G No speed caps or throttling No contract No credit check EU roaming included

1p Mobile 10GB

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texts Unlimited
Minutes Unlimited
Data 10GB
Contract 30-day rolling plan
Monthly cost £8 /mth
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UK's best coverage on 2G, 4G & 5G No speed caps or throttling No contract No credit check EU roaming included

1p Mobile Unlimited

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texts Unlimited
Minutes Unlimited
Data Unlimited
Contract 30-day rolling plan
Monthly cost £25 /mth
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UK's best coverage on 2G, 4G & 5G No speed caps or throttling No contract, 30-day rolling No credit check EU roaming included

1p Mobile 50GB

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texts Unlimited
Minutes Unlimited
Data 50GB
Contract 30-day rolling plan
Monthly cost £10 /mth
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UK's best coverage on 2G, 4G & 5G No speed caps or throttling No contract, 30-day rolling No credit check EU roaming included

Lebara Unlimited - International

International Calls & Data SIM Only Plan

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texts Unlimited
Minutes Unlimited
Data Unlimited 4G & 5G
Contract 30-day rolling plan
Monthly cost £30 /mth
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No Annual Price Rises Use your plan in the EU or India at no extra cost (up to 30GB data). Runs on Vodafone network No credit checks 1000 International Minutes

Lebara 5GB

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texts 1000
Minutes 1000
Data 5GB
Contract 30-day rolling plan
Monthly cost £5 /mth
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No Annual Price Rises Use your plan in the EU or India at no extra cost (up to 30GB data). Runs on Vodafone network No credit checks 1000 International Minutes

Lebara 50GB

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texts Unlimited
Minutes Unlimited
Data 50 GB
Contract 30-day rolling plan
Monthly cost £9 /mth
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No Annual Price Rises Use your plan in the EU or India at no extra cost (up to 30GB data). Runs on Vodafone network No credit checks 1000 International Minutes

How to Choose the Best SIM-Only Deal

Choosing the best SIM-only deal depends largely on how you use your phone each day. With hundreds of SIM-only plans available in the UK, comparing the key features can help you find the right balance between price, data, and flexibility.

Unlike traditional mobile contracts that include the cost of a handset, SIM-only deals provide a SIM card that works with your existing phone. This means you avoid paying for a new device and can access much cheaper monthly plans while still benefiting from the same network coverage, call allowances, and data speeds.

Because of this, SIM-only contracts have become one of the most popular ways to get affordable mobile service in the UK. Many networks now offer competitive plans with generous data allowances, unlimited calls and texts, and even 5G connectivity at no extra cost.

Before switching, it’s important to consider how much data you need, how long you want to commit to a contract, and which mobile network provides the best coverage in your area.

Key Features to Compare in SIM-Only Plans

Feature Why It Matters
Data Allowance Heavy streaming, gaming, or social media users will benefit from larger data plans.
Contract Length 30-day rolling deals offer flexibility, while 12-month plans are usually cheaper.
Network Coverage Coverage varies across the UK, so choosing a reliable network is essential.
5G Availability Faster speeds and lower latency in supported areas.

Understanding these factors will help you find the best value SIM-only contract for your needs.

Tip: If you regularly use WiFi at home or work, a smaller data allowance could save you money.

Do You Need an Unlocked Phone?

Most modern smartphones are now sold unlocked, meaning they can work with SIM cards from any network. If your phone was purchased on a contract, it may previously have been locked to a specific provider. Unlocking your phone allows you to:
  • Switch networks easily
  • Compare better deals
  • Avoid long-term contracts

Using eSIM With SIM-Only Plans

Many modern smartphones now support eSIM technology, allowing you to activate your mobile plan digitally. Instead of inserting a physical SIM card, you simply scan a QR code provided by your network to activate your plan. Benefits of eSIM include:
  • Faster activation
  • No physical SIM required
  • Ability to store multiple network profiles

SIM-Only vs Phone Contracts

Looking for the best SIM-only deal in the UK? SIM-only plans usually cost less than traditional phone contracts and give you the freedom to switch networks or upgrade your plan whenever you want. Compare the key differences between SIM-only plans and phone contracts to find the right choice for your lifestyle.
Feature SIM-Only Phone Contract
Monthly Cost Lower Higher
Contract Length Flexible Usually 24 months
Includes Phone No Yes
Upgrade Freedom Anytime Limited
If you already own a smartphone, SIM-only deals are usually the cheapest option.

Start Saving on Your Mobile Plan Today

Switching to a SIM-only plan is one of the easiest ways to cut costs and get more value. Compare deals to:
  • Find the perfect plan for your data, calls, and texts
  • Switch networks without losing your number
  • Enjoy flexible contracts and better perks
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