You'll find the best SIM-only deals available in the UK right now below. For expert SIM buying advice and even more deals hand-picked by the team at PC Advisor, continue reading.

Also see: Best Phone Deals

Best SIM-only deals 2017 UK

Best SIM-only deals 2017 UK: SIM-only deals explained

If you're new to the idea of a SIM-only deal, we've got everything covered below, but if you already know what type of user you are and have a good idea of what you're looking for, you can skip ahead using the following links:

Unlike smartphone contracts, which typically stretch to 24 months, SIM-only deals are much shorter. Most SIM-only deals come with 12-month contracts, but you can also get rolling monthly contracts – sometimes at the same price or just a few pounds more expensive – that are ideal for visitors to the UK.

And then there are pay-as-you-go plans, so you can pay just for what you need when you need it, although you can expect these to work out more expensive.

The price you pay per month will largely depend on how many minutes and texts you need, and how much data you require. Plus, you'll need to decide whether you need 3G or 4G data and whether your SIM is to go in a tablet (in which case you'll only need data) or a smartphone (in which case you'll want minutes, texts and data). It's worth noting that most operators don't allow you to simply take your SIM out of your smartphone in a tablet. They also often frown upon tethering.

While 4G is much faster than 3G connectivity, 4G data is sometimes more expensive than 3G data. However, just because your phone or tablet might support 4G, it doesn't mean you have to take advantage of that connectivity if it can save you money not to. Some carriers charge the same amount for 3G and 4G data, though.

Best SIM-only deals 2017: Smartphone plans

Pinning down what is the best SIM-only smartphone deal is tricky due to the huge number of combinations of minutes, texts and data available. However, most people will fall into one of three camps that we'll focus on here: those who simply want to make the odd call or text, and use their PC to go online; those who make calls and texts, go online, check emails, use apps and perhaps watch the odd video; and those who are permanently glued to their smartphone. Or, to put that more simply, light-, moderate- and heavy users.

Best SIM-only deals 2017 UK: Limited time offers

You'll find some half price deals over at TalkTalk, including one that gets you 250 minutes, unlimited texts and 300MB of data for a tiny £3.95 per month. View deal here.

Best SIM-only deals 2017 UK: SIM deals for light use

There are several plans available for just £5 per month if you plan on using your SIM for light use.

BT Mobile offers 200 minutes, unlimited texts and 500MB of data for £5, but that's only for existing BT Broadband customers. It's a 12-month contract and includes 4G, so it's a really good, cheap deal that's worth considering if you're a customer already and don't need loads of minutes and only occasionally need to use data.

  • 500MB data, 200 minutes, unlimited texts, 4G - £5 per month. View deal here

Alternatively, Virgin Media offers a 30-day rolling contract that isn't exclusively for its broadband customers for just £5. It offers 250 minutes, unlimited texts and 250MB data. It doesn't offer 4G, though, only 3G.

  • 250MB data, 250 minutes, unlimited texts, 3G - £5 per month. View deal here.

You should also consider iD, which is Carphone Warehouse's mobile network. It offers a capped SIM for just £4 on its ShockProof plan type, which offers 250 minutes, 5,000 texts and 250MB data on a one month rolling contract. This SIM is designed to cut you off if you go over your minutes, texts or data to make sure you don't have any nasty surprises when you get the bill through at the end of the month.

If you want a bit more data there's a £5 per month option with 1GB instead of 250MB.

  • 250MB data, 250 minutes, 5,000 texts, 4G, - £4 per month. View deal here.
  • 1GB data, 250 minutes, 5,000 texts, 4G - £5 per month. View deal here.

Best SIM-only deals 2017 UK: SIM deals for moderate use

For moderate users, the best deals tend to be around the £10 mark for SIM-only plans.

iD has announced a new feature for its SIM-only deals called Data Rollover. This means that if you have any data left over on your monthly plan it can be carried over into the next month. The data only rolls over for one month before expiring, though.

iD Data Rollover is best for moderate users. One of the best Data Rollover contracts is the £7 per month rolling contract that offers 500 minutes, 5,000 texts and 1GB of 4G data.

If you don't need many minutes but want a little more data there's the iD ShockProof rolling contract capped at 250 minutes, 5,000 texts and 2GB data for £7.50 per month, but you don't get the Data Rollover feature here.

Another moderate option is iD's £9 per month GoTo Data Rollover plan, which gives you 500 minutes, 5,000 texts, 2GB data on a rolling 4G plan.

  • 1GB data, 500 minutes, 5,000 texts, 4G - £7 per month. View deal here.
  • 2GB data, 250 minutes, 5,000 texts, 4G - £7.50 per month. View deal here.
  • 2GB data, 500 minutes, 5,000 texts, 4G - £9 per month. View deal here.

There are other moderate deals at decent prices, as listed below, but none of them can quite match iD's current pricing, so it'll depend whether you've got a particular preference for a network you've been on before or have been recommended.

For example, Giffgaff's £10 Goodybag is good for moderate users, offering 500 minutes, unlimited texts and 1GB of 4G internet, with free Giffgaff to Giffgaff calls on top of that. This is a one-month contract that you can set to auto-renew, but with Giffgaff you also get the flexibility to swap to a different Goodybag if you feel like you need more minutes, data or texts, or if you need less.

  • 1GB data, 500 minutes, unlimited texts, 4G - £10 per month. View deal here.

Three also offers good moderate use SIM-only deals, and with Three you get the added bonus of being able to use your phone abroad at no extra cost. For example, for £11 per month you can get 2GB data, 200 minutes and unlimited texts on a 4G, 12-month contract. Alternatively, Three offers 1GB data and 600 minutes for the same price. Plus, right now you'll get a £50 Amazon gift card with these plans.

  • 1GB data, 600 minutes, unlimited texts, 4G - £11 per month. View deal here.
  • 2GB data, 200 minutes, unlimited text, 4G - £11 per month. View deal here.

Best SIM-only deals 2017 UK: SIM deals for heavy use

For anyone who wants the freedom to text and use the internet as much as they like, our favourite deal is Three's 30GB data, unlimited texts and 200 minutes contract, which is a very reasonable £20 per month.

  • 30GB data, 200 minutes, unlimited texts, 4G - £20 per month. View deal here.

A good, affordable option for heavy users is Giffgaff's £15 Goodybag, which offers 1,000 minutes, unlimited texts and 4GB data. Other options include the £18 Giffgaff Goodybag with 2,000 minutes, unlimited texts and 6GB data.

  • 4GB data, 1,000 minutes, unlimited texts, 4G - £15 per month. View deal here.
  • 6GB data, 2,000 minutes, unlimited texts, 4G - £18 per month. View deal here.

Best SIM-only deals 2017 UK: Tablet plans (Data SIMs)

As we mentioned earlier, you can't simply take the SIM out of your phone and stick it in your tablet. You need to get a SIM that uses a data-only plan (and don't forget that not all tablets offer SIM-card slots, in which case you'll only be able to connect to WiFi).

How much data you need will very much depend on the activities you intend to enjoy on your tablet, plus whether you spend any of your time within range of a Wi-Fi hotspot. If you want a SIM just to cover you on the odd occasion that you use your tablet away from home and need to continue to access your email, you certainly don't need to pay out extra for a 4G plan.

Some of the best SIM-only deals for tablets come from Three, which offers 1GB for £7.50 per month, 2GB for £8 per month, 5GB for £13 per month or 15GB for £18. You can view those deals here.