The Best SIM for Your Car: Which Data SIM Card Should You Get For In-Car Wi-Fi?

by Sandra Henshaw - , Last Updated on June 14, 2019, Buying Guides

Our world is getting smarter. From Internet-connected TVs to home assistants like Google and Alexa, we’re coming to depend on technology more and more. And cars are no exception to this rule.

Many cars nowadays come with a SIM card slot. What’s it for? Should you grab a new SIM card to fill that slot? That’s what we’re here to find out. We’ve got everything you need to know about car SIMS.

What’s the Deal?

in car sim slot

Certain models of car have SIM card slots. Why? Well, you’re so connected in the rest of your life, why wouldn’t you want to stay connected in your car as well? Adding a SIM card to your car can do tons of cool, internet-based things, such as:

  • Allowing live traffic updates to your sat-nav or GPS system
  • Allowing music streaming to your in-car speakers from online services like Spotify
  • Allowing calls and texts to come through to your car’s dashboard/speakers rather than to your phone
  • Allowing others in your car to use the car’s SIM as a WiFi hotspot so they can get online with their devices
  • Allowing streaming of videos and movies to backseat screens to keep the kids entertained
  • Allowing real-time directions to wherever you’re going
  • Allowing you to “talk” to smart home devices you might have like lights and heating systems to ensure your home is warm and well-lit when you get there

And so much more. Having some kind of data connection in your car can be pretty awesome, though filling up that SIM slot might not exactly be necessary, as we’re about to find out.

Which Cars Are We Talking About?

car brands

There are a fair few models now that come with SIM card slots, including cars from BMW Connected Drive, Skoda, Audi Connect, Volkswagen Connect and more. The list is growing as most upper-end new cars are starting to feature a way to get your vehicle online.

Three Data Reward SIM

Our favourite SIM for your car

Three Data Reward SIM

If you don’t want to read our full guide on which SIM is best for in-car use, then our advice is to get a Three Data Reward SIM as they are ideal for the vast majority of users.

This is a PAYG SIM that costs £10 initially and comes preloaded with 1 GB of data. After that, every 30 days you get 200 MB of data free of charge. It’s a data only SIM, so there’s no minutes or texts.

Firstly, this SIM gives you a great chance to check out just how much data you really need. Use it for a month with that included 1 GB of data and see how much data you use. If you use under 200 MB then keep the card, since you’ll get 200 MB of free data every month anyway. That way, this SIM won’t end up costing you anything in the long run.

Even if you use over 200 MB a month it might still be worth keeping the SIM. For everything over that free 200 MB, you pay just 1p per MB, which isn’t a ton. Three also has data packages that let you add more data for a set price every 30 days which is ideal if you’re going on a longer road trip or know you’ll be using more data in a particular month.

Get Data Reward SIM

Do I Really Need a SIM Card?

why need

Just because your car has a SIM card slot though doesn’t necessarily mean that you need to go out and get a new SIM, or that you need to go completely unconnected. There are really three options available to you, each has its pros and cons, and you might find that not getting a SIM at all is the best way to go, depending on what you need.

Method 1: No SIM At All

Your first option is not to get a new SIM at all. You can quite easily plug your smartphone into your car, fire up Android Auto or Apple Car Play (which most new cars now have) and be on your way. Your car will use your phone’s SIM and data to get the information it needs for all kinds of things, and you’ll be able to take calls through your car speakers. This may or may not give you live traffic updates and directions, depending on how your car works and what kind of sat-nav or GPS you’re using. But Google Maps or Waze are often better than the built-in nav.

This is obviously the simplest way to get your smart car going. You’ll get plenty of connectivity and won’t need to worry about a new SIM card, new phone bills, or putting credit on a PAYG SIM. However, it’s not a perfect solution. Your car could end up eating through your phone’s monthly data limit pretty quickly, depending on what you’re doing. And just how well connected your car is going to be using just your phone depends on your make and model, and there may be some functions that don’t work without an in-car SIM.

Pros:

  • No new SIM card necessary, no extra phone bills
  • Easy to set up, simple to use
  • Major functions like calling and texting and music streaming should work just fine using your phone

Cons:

  • Not all functions will work properly using only your phone, and you may miss out on some manufacturer specific features
  • You may find that your car eats into your phone’s monthly data limit quickly, leaving you with less data to use when you’re not in the car

Best For:

Those who don’t mind having their phone connected to the car at all times and prefer using Android Auto or Apple Car Play compared to the inbuilt car system.

Your other two options involve getting a SIM card, which is a little extra trouble but could be a good decision depending on your needs.

Method 2: Get a Data-Only SIM

So you’ve decided that getting a SIM is a good choice for you. Perhaps you don’t often plug in your phone to your car, perhaps there are functions you want to use that your phone data connection doesn’t support. Perhaps you’re just blowing through your phone’s data plan to fast. Getting a SIM should allow you to use all of your car’s functions. Your first option is to go for a data only SIM.

A data-only SIM is exactly what it sounds like, a SIM card that contains a data allowance but no calling minutes or texts. Since most people only want to use data through their car’s system, this could be the ideal solution, you won’t be paying for services that you’re not using. You can get a preloaded data-only SIM, or you can get a contract, it’s really up to you, and we’ll look at the pros and cons of that below. The important thing is that you’ll have data.

Any downsides? Well, that depends. Some people do want to be able to call and send texts through their car itself, in which case a data only SIM won’t be suitable for you. Though to be fair, most of us can use Bluetooth to keep our phones connected for those calls. You should also be aware that just because a data only SIM includes only data doesn’t necessarily mean that it’s the cheapest plan. In some cases, regular SIM plans (with minutes and texts) are cheaper, so you’ll need to compare plans with different networks to find out.

Pros:

  • You can use nearly all of your car’s functions without a problem
  • You can choose between PAYG or pay monthly, meaning there are lots of options and budget ranges
  • Buying data for your car is an extra expense, but is likely cheaper than going over the data limit on your phone plan, since operators charge a lot for extra data

Cons:

  • You won’t be able to make calls or send texts through the in-car system, though you will still be able to use your Bluetooth connected phone to call and text
  • May not be the cheapest option, since sometimes regular SIM plans (with minutes and texts) end up being cheaper

Best For:

Anyone that wants to get a data connection in their car and wants to use all functions. Anyone that doesn’t want to make calls through the in-car system. Basically, this is probably the best bet for most people.

Method 3: Get a Regular SIM

Your final option, rather obviously, is just to go ahead and get a regular SIM card. This will allow you to do anything you want in your car, from making calls to streaming music. It may or may not be cheaper than using a data only SIM, that depends on the plan you choose. And again, you can choose between PAYG and pay monthly options.

The only real downside of this is more of a mild inconvenience. A regular SIM card put into your car and used for calls and texts will have a different phone number from your regular phone SIM. This probably isn’t a real issue, but it’s something to keep in mind.

Pros:

  • Let’s you do anything you like in your connected car
  • PAYG and contract options mean there’s lots of choice and plans for lots of different budgets

Cons:

  • Calls and texts coming from an in-car SIM will have a different phone number than those coming from your normal mobile
  • May or may not be more expensive than a data only SIM, depending on the plan you choose

Best For:

If you’re looking to make calls through your in-car system without using your mobile and Bluetooth, then this is the choice for you. Depending on costs it may also be a good choice for everyone else. If you can get a regular SIM plan more cheaply than a data only SIM plan, then take the cheaper plan (it won’t matter that you don’t use the call and text allowance).

What Am I Looking for in a SIM Card?

looking for

If you’ve opted to buy a SIM card then we do have some plan recommendations for you that you’ll find below. But really there are two things that you’re looking at when choosing a plan:

Data Limit

Since you’re pretty much getting a SIM card for its data so that your car can get online obviously data is the most important thing that you’re looking at. How much data do you need? Probably not as much as you’d think. Unless you’re frequently streaming music or video to back seat screens you can almost certainly get away with less than 1 GB a month.

However, it’s tough to tell, since we don’t know how you’re going to be using your SIM. If you’re unsure then your best bet is going to be opting for a simple PAYG SIM for a month to find out how much data is a reasonable estimate for you.

Cost

The second thing that you’ll want to look at is cost. SIM plans range tremendously in cost, so putting in the time to do a little research to find the best deal will be to your benefit. We’ve said this above, but it’s worth repeating: a data only SIM will not necessarily be cheaper than a regular SIM. You’ll really need to compare options to find the best prices (though again, we do have some recommendations below).

PAYG vs. Contract: Which is Best?

payg vs contract

Should you be looking at PAYG or contract options? Again, that’s your decision. As a general rule, PAYG options are more flexible. You’re not tied to a contract, you can stop using the card any time you like. You won’t have to pay a monthly bill, you can just top up with credit when you need it (handy if you’re not using your car on a daily basis). However, if you’re a big user then prices on contracts tend to be cheaper per MB of data.

Compare your options before you decide. But do keep in mind that a contract will require that you pass a credit check. And once signed, that contract can be difficult and costly to break, so be sure that you can commit before signing on the dotted line.

Which Car SIM Plans Are Best?

All of that being said you should have a clearer idea of what you’re looking for. And we do have a few recommendations for plans that you should take a look at.

Best Plan for Low In-Car Usage

three-unlimite-data-sim

If you’re just getting started in the process of using a SIM card in your car then our top recommendation goes to Three’s Data Reward SIM, for a few reasons. This is a PAYG SIM that costs £10 initially and comes preloaded with 1 GB of data. Every 30 days you get 200 MB of data free of charge. It’s a data only SIM, so there’s no minutes or texts.

However, this SIM gives you a great chance to check out just how much data you really need. Use it for a month with that included 1 GB of data and see how much data you use. If you use under 200 MB then keep the card, since you’ll get 200 MB of free data every month anyway. That way, this SIM won’t end up costing you anything.

Even if you use over 200 MB a month it might still be worth keeping the SIM. For everything over that free 200 MB, you pay just 1p per MB, which isn’t a ton. Three also has data packages that let you add more data for a set price every 30 days. However, these probably aren’t the best deal for big data users (we’ll get to a plan for you in a minute).

Best Pure PAYG SIM

1p-mobile

If you’re looking for a pure PAYG SIM then we suggest 1p Mobile’s PAYG programme. As the name implies, you pay 1p per calling minute, 1p per text message, and 1p per MB of data, which are pretty low prices. For data you might want to add a data pack to get even cheaper prices. For just £4 you can add 500 MB of data to your card, and that’s valid for 30 days.

In terms of convenience and price, it doesn’t get much easier than 1p Mobile. It’s not the biggest operator in the country, but this is still a great deal for those that don’t want to commit to a contract.

Best Big Data PAYG SIM

Three PAYG

If you’re looking for a lot of data then as a general rule Three is nearly always going to be your best bet. However, big data deals are cheaper on regular SIMs than on data-only SIMs. Depending on how much data you need you’ll need to add a 30-day bundle to your PAYG card. This will give you an allotment of minutes, texts, and data, and unused minutes/texts/data will disappear after 30 days, at which point you’ll need to renew the bundle. Three had a ton of bundle offers with lots of data, so depending on your needs, here are your options:

  • 5 GB of data plus unlimited texts and calls for £15 for 30 days
  • 12 GB of data plus unlimited texts and calls for £20 for 30 days
  • 36 GB of data plus unlimited texts and calls for £27.50 for 30 days
  • Unlimited data, minutes, and texts for £35 for 30 days

Best Cheap Contract Option

Vodafone

If you’re looking for cheap contract options with above average usage, we recommend Vodafone’s 12-month contract. You’ll pay £8 a month, and in that price, you’ll get 3 GB of data, unlimited texts and unlimited minutes. Okay, you might not need those minutes and texts, but it’s still relatively cheap.

Best Big Contract Option

Three SIM Card

If you want a contract that’s a little meatier and that contains plenty of data then we’d recommend looking at Three again. They currently offer a 12-month contract that costs £13 a month and that comes with 20 GB of mobile data. That should be more than enough for even the biggest of data users.

Car SIMs: The Bottom Line

Choosing whether or not to put a SIM card into that SIM slot in your car really depends on how you plan on using your cars data capabilities. Being online inside your vehicle can be useful. On the other hand, others may find it distracting. You’ll need to think carefully about how you plan on using your vehicle, and about the cost implications of choosing to add or not add a SIM card. The good news is that for a relatively low amount of cash you can get your car online if you choose to.