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SIM Only Help & Guides

Our SIM Only Guides explain basics of SIM Only deals, including how to keep your number when switching networks, what SIM card you need for your phone, and how SIM Only contracts work.

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Consumer Rights

Which Mobile Networks Offer Spending Caps?

Which Mobile Networks Offer Spending Caps?

Last updated: 17th May 2026

Your mobile phone bill can often be stressful, especially if you are...

What Is Ofcom? What Does It Do?

What Is Ofcom? What Does It Do?

Last updated: 22nd March 2026

It seems that not a week goes by without Ofcom being mentioned in the...

Coverage & Roaming

1pMobile Roaming Explained: EU and Worldwide Charges 2026

1pMobile Roaming Explained: EU and Worldwide Charges 2026

Last updated: 16th July 2026

1pMobile includes EU roaming on every plan, and unusually its 46...

O2 Roaming Explained: EU and Worldwide Charges 2026

O2 Roaming Explained: EU and Worldwide Charges 2026

Last updated: 26th July 2026

O2 is the only major UK network that has not reintroduced EU roaming...

Spusu Roaming Explained: EU and Worldwide Charges 2026

Spusu Roaming Explained: EU and Worldwide Charges 2026

Posted: 4th June 2026

Spusu includes EU roaming on every plan, but with a twist that catches...

Honest Mobile Roaming Explained: EU and Worldwide Charges 2026

Honest Mobile Roaming Explained: EU and Worldwide Charges 2026

Last updated: 8th July 2026

Honest Mobile handles roaming differently from almost every other UK...

Three Roaming Explained: EU and Worldwide Charges 2026

Three Roaming Explained: EU and Worldwide Charges 2026

Posted: 4th June 2026

Whether you pay anything to use your phone abroad on Three depends on...

giffgaff Roaming Explained: EU and Worldwide Charges 2026

giffgaff Roaming Explained: EU and Worldwide Charges 2026

Posted: 2nd June 2026

giffgaff includes EU roaming on its plans, but its allowance works...

SMARTY Roaming Explained: EU and Worldwide Charges 2026

SMARTY Roaming Explained: EU and Worldwide Charges 2026

Posted: 2nd June 2026

SMARTY includes EU roaming on every plan with a 12GB monthly cap, and...

Honest Mobile Smart SIM Review: I Tested It Across Three Countries

Honest Mobile Smart SIM Review: I Tested It Across Three Countries

Last updated: 8th July 2026

I had been using Honest Mobile's Smart SIM in the UK for eight months...

Your Ultimate Guide to Network Coverage

Your Ultimate Guide to Network Coverage

Last updated: 17th May 2026

Reliable mobile phone coverage is no longer a luxury but an absolute...

EU Roaming Charges Explained: Every UK Network Compared

EU Roaming Charges Explained: Every UK Network Compared

Last updated: 27th July 2026

Data roaming comes into play when you travel outside the UK, and your...

Family & Kids

The Best SIM-Only Deals for Families

The Best SIM-Only Deals for Families

Last updated: 17th May 2026

Are you looking for a simple way to save money on your family's mobile...

Best SIM Only Deals for Kids

Best SIM Only Deals for Kids

Last updated: 17th May 2026

Choosing the right SIM-only deal for a child or teenager requires...

Features & Tech

Are eSIMs Only for Travel? Using an eSIM as Your Main UK SIM

Are eSIMs Only for Travel? Using an eSIM as Your Main UK SIM

Last updated: 27th July 2026

No, eSIMs are not only for travel. You can use an eSIM as your main UK...

Which Networks Offer eSIMs on Pay As You Go?

Which Networks Offer eSIMs on Pay As You Go?

Last updated: 16th July 2026

Pay As You Go eSIMs let you use a digital SIM without a contract or...

What is Wi-Fi Calling - Which UK Networks Support It?

What is Wi-Fi Calling - Which UK Networks Support It?

Last updated: 4th April 2026

Wi-Fi calling lets you make and receive standard phone calls over a...

What Is An eSIM? Which UK Networks Support Them?

What Is An eSIM? Which UK Networks Support Them?

Last updated: 16th July 2026

An eSIM is a digital SIM built into your phone, letting you join a...

Networks & MVNOs

Why Is Smarty So Cheap?

Why Is Smarty So Cheap?

Last updated: 27th July 2026

Smarty regularly sells plans for less than comparable deals from the...

Sky Mobile Review 2026: How Does It Compare?

Sky Mobile Review 2026: How Does It Compare?

Last updated: 16th July 2026

Sky Mobile is the mobile arm of Sky, running on O2’s network and best...

1pMobile Review 2026: How Does It Compare?

1pMobile Review 2026: How Does It Compare?

Last updated: 16th July 2026

1pMobile is a prepay MVNO on EE’s network, best known for the tariff it...

Smarty Review 2026: How Does It Compare?

Smarty Review 2026: How Does It Compare?

Last updated: 27th July 2026

Smarty is a budget MVNO owned by Three, selling 30 day rolling plans...

Honest Mobile Review 2026: How Does It Compare?

Honest Mobile Review 2026: How Does It Compare?

Last updated: 27th July 2026

Honest Mobile is the only UK network where your bill goes down the...

Mozillion Review 2026: How Does It Compare?

Mozillion Review 2026: How Does It Compare?

Last updated: 7th July 2026

Mozillion is a UK MVNO running on EE's network, best known as a...

Which Networks Use Three? Honest Mobile, iD Mobile and Smarty Compared

Which Networks Use Three? Honest Mobile, iD Mobile and Smarty Compared

Last updated: 2nd June 2026

Three MVNOs use Three's network in the UK: Honest Mobile, iD Mobile...

Which Networks Use Vodafone? Asda Mobile, Lebara, Talkmobile and Voxi Compared

Which Networks Use Vodafone? Asda Mobile, Lebara, Talkmobile and Voxi Compared

Last updated: 2nd June 2026

Four MVNOs use Vodafone's network in the UK: Asda Mobile, Lebara...

Which Networks Use EE? 1pMobile, Lycamobile, Spusu and More Compared

Which Networks Use EE? 1pMobile, Lycamobile, Spusu and More Compared

Last updated: 2nd June 2026

Seven MVNOs use EE's network in the UK: 1pMobile, EcoTalk, Grade...

Which Networks Use O2? Chattr, Giffgaff, Sky Mobile and Tesco Mobile Compared

Which Networks Use O2? Chattr, Giffgaff, Sky Mobile and Tesco Mobile Compared

Posted: 19th May 2026

Four MVNOs use O2's network in the UK: Chattr, Giffgaff, Sky Mobile...

Best Network for International Calling from the UK

Best Network for International Calling from the UK

Last updated: 17th May 2026

If you regularly call family or friends in another country from your UK...

Lycamobile Review 2026: How Does It Compare?

Lycamobile Review 2026: How Does It Compare?

Last updated: 17th May 2026

Lycamobile Review 2026: How Does It Compare? Reviewed by: Phil Brown...

Spusu Review 2026: How Does It Compare?

Spusu Review 2026: How Does It Compare?

Last updated: 16th July 2026

Spusu has quietly become one of the most talked about budget MVNOs in...

What Is an MVNO (Mobile Virtual Network Operator)?

What Is an MVNO (Mobile Virtual Network Operator)?

Last updated: 23rd May 2026

A mobile virtual network operator, commonly abbreviated to MVNO, is a...

Plans & Pricing

Is 10GB of Data Enough?

Is 10GB of Data Enough?

Last updated: 27th July 2026

10GB sits at the budget end of the UK market, and for the right person...

Is 100GB of Data Enough?

Is 100GB of Data Enough?

Last updated: 27th July 2026

100GB covers more usage than most heavy users ever reach, and it...

Is 30GB of Data Enough?

Is 30GB of Data Enough?

Last updated: 27th July 2026

30GB sits in the middle of the UK market and is the allowance most...

How Much Mobile Data Do I Need?

How Much Mobile Data Do I Need?

Last updated: 27th July 2026

Most people pay for more mobile data than they actually use. This guide...

SIM Only Mid-Contract Price Rises: What You Need to Know (2026)

SIM Only Mid-Contract Price Rises: What You Need to Know (2026)

Last updated: 9th July 2026

Staying connected with a SIM-only plan is one of the most popular ways...

Which Networks Offer SIM-Only Data Rollover?

Which Networks Offer SIM-Only Data Rollover?

Last updated: 4th June 2026

Are you looking for a SIM-only deal? There are plenty of factors to...

What is a One Month Rolling SIM Contract?

What is a One Month Rolling SIM Contract?

Last updated: 11th July 2026

A one month rolling SIM contract is a SIM-only plan that renews...

Is Unlimited Data Really Unlimited?

Is Unlimited Data Really Unlimited?

Last updated: 8th July 2026

Most unlimited data plans in the UK are genuinely unlimited in the...

SIM-Only Basics

Why SIM-Only Deals are the Smartest Choice for Cutting Your Mobile Phone Costs

Why SIM-Only Deals are the Smartest Choice for Cutting Your Mobile Phone Costs

Last updated: 17th May 2026

If your phone contract has ended and you are still paying the same...

What is a SIM-Only Deal?

What is a SIM-Only Deal?

Last updated: 22nd March 2026

A SIM-only deal is a mobile phone plan that gives you a monthly...

Switching & Setup

How to Check if Your Phone is Unlocked

How to Check if Your Phone is Unlocked

Last updated: 22nd March 2026

An unlocked phone can be used with any UK mobile network. A locked...

What SIM card do I need for my phone?

What SIM card do I need for my phone?

Last updated: 16th July 2026

The SIM card you need depends on your phone model and whether it...

How do I keep my number when switching to SIM only?

How do I keep my number when switching to SIM only?

Last updated: 11th July 2026

Keeping your existing mobile number when you move to a new SIM-only...