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Our phones are part of our everyday lives, allowing us to stay connected with just the tap of a finger. But have you ever thought about what makes things like making phone calls and texting possible?

It's all thanks to that little removable card we call a SIM card.

This guide will provide everything you need to know - from how they function in connecting us with our cell network right down to the features and benefits a SIM card brings.

What is a SIM card?

A Subscriber Identity Module (or SIM card) is like a mini-computer tucked away in your cell phone, tablet, or hotspot device.

It's the key to connecting you with your wireless carrier's network and all the data it has to offer.

Without one of these little cards, no texting, calling, or internet browsing would be possible - so they definitely do their part.

Where can you get a SIM card?

When you sign up for a cell phone plan, your carrier sends out your free SIM card kit. As long as your device is compatible, you can just pop it into your device and follow the steps to get your new plan live.

How much are SIM cards?

There isn't a standard cost for SIM cards because it's the cell phone plan you're paying for, not the SIM card. So, the price actually depends on which cell phone plan works best for you. With MVNOs like Tello and Mint Mobile, plans start from just $10 a month with your prepaid SIM card included. Explore the best MVNOs to see what suits you most.

What size SIM card do I need?

SIM cards are available in three different sizes;

  • Standard
  • Micro
  • Nano

The SIM card size you'll need will depend on your cell phone. Most smartphones now use a nano-SIM, but some older models will use a standard or micro SIM.

Many cell phones made from around 2018 onwards provide dual SIM functionality, so you'll also have the option to choose an eSIM plan (embedded SIM).

How to remove SIM cards from your phone

First, you'll need to locate where it is stored on your phone - most handsets will have a slot along the side.

Don't worry if you don't have that special removal tool; a paperclip should do. Carefully open up the case and take out the SIM card.

How do I activate my SIM card?

Each carrier is different, so to activate your SIM card, you'll need to pop the SIM card into your phone. Then follow your new carrier's instructions. You'll be up and running before you know it.

Can you change SIM card settings?

Your SIM card is unique to the carrier's network, and its settings cannot be changed.

However, you can move your SIM card between compatible cell phones and also take your number with you if you switch carriers.

What's a data SIM card?

If you aren't bothered about making or receiving calls and just want data-only for getting online, a data only SIM card is the perfect solution.

Ideal for a tablet or mobile hotspot device, a data SIM card allows you to connect to the carrier's network for internet use, like browsing the internet, streaming music and movies, checking emails, and online gaming using mobile data.

How much data will I need?

How much data you need for your data-only SIM will depend on what you're using it for. If you won't be connected to Wi-Fi often, you'll need more than someone who spends most of their day at home or in an office.

Can I use my SIM card in another phone?

Yes, you can move your SIM card between cell phones as long as the phone is unlocked and compatible with the SIM card carrier's network.

AT&T and T-Mobile operate on the GSM network, and Verizon runs on the CDMA network. So, it depends on which network your low-cost carrier is powered by.

What's a prepaid SIM card?

With prepaid SIM cards from an MVNO, you don't need to sign a contract for your cell phone plan. It's almost like having the freedom of a pay-as-you-go service with all the benefits and features that come with signing up for long-term plans.

You can make calls, send texts, and choose a data allowance - so you'll never be caught out by costly overage fees. Plus, you can also cancel or amend your plan at any time if your needs change.

Cheapest prepaid SIM cards

MVNOs offer the best SIM card deals at affordable prices for any budget. They make buying a SIM card easy. You can compare and choose your cell phone plan without leaving your house. And your SIM card is sent to you within a few days.

Even better, if you have an eSIM-compatible phone, you could be up and running on your new plan within a few hours.

Most MVNO plans offer unlimited calls and text messages with a range of data allowance options.

International SIM cards

If you're traveling, buying a local prepaid SIM card offers more value for money. Using a local SIM card means you'll be connected to a local mobile network.

The benefits of using local SIM cards when you're in other countries can help you save money on data roaming charges from your own provider. Whether you're in South America, a European Country, or Australia, you can purchase an international SIM card in most countries.

Just be sure to check your cell phone is unlocked and can accept SIM cards from other networks.

You can also find a variety of International SIM cards from MVNOs offering free international calling and texts.

What is an eSIM?

An eSIM (embedded subscriber identity module) is built into the device, unlike physical SIM cards, which are removable.

The iPhone 14 models have revolutionized the cell phone industry with their use of eSIM technology. Previously, cell phones had started to adopt dual SIM to allow for both eSIM and physical SIM, whereas the iPhone 14 cell phones are the first phones to support eSIM only. And with their latest iPhone 15 models doing the same, this should help prompt more eSIM compatibility from low-cost carriers.

How does eSIM work?

An eSIM works exactly the same, except without the physical SIM card.

You can enjoy all of the same benefits as a traditional SIM card - but as the eSIM is built into your phone, you don't have to wait for your SIM card to arrive in the post. You can have your new plan up and running within a few minutes rather than days.


In this ultimate guide to SIM cards, we've covered staying connected when you're traveling, the best-prepaid plans, data-only SIMs, what a SIM card is, and how to activate or remove your SIM card.

MVNOs offer the cheapest prepaid phone plans with something for all budgets and needs. With their customizable plans, you can check for plans that offer free roaming, WiFi hotspots, unlimited data usage, and more.

A prepaid SIM card plan gives you more freedom and flexibility, and most low-cost carriers have no hidden fees. In our eyes, it's a no-brainer!

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