Buying a Short-Term UK SIM Card for Cheap: Mobile Carrier Cost Comparisons and Other Tips

Greg Lane

Travelling without constant data these days is almost unthinkable. Getting from the station to your accommodation? You’re probably going to want to follow that little blue dot on the screen all the way to your bed for the night. Luckily, getting a good-value prepaid/pay-as-you-go UK SIM card is very easy.

london sim card
Photo by Gregory Lane
Here for more than 30 days? See our post on UK SIM cards for longer-term use.

Keep calm and use wifi

The good news about London is that pretty much everywhere you go there’ll be some kind of open wifi network, starting with the airport. Don’t be tempted to get a PAYG UK SIM at the airport, because there’s a good chance it won’t be the best deal available.

Do you even need a UK SIM card?

If you’re lucky enough to be an EU resident, or you started your trip in another EU country, then Brussels has you covered; you can roam for free in London. Increasingly, non-EU mobile companies are also offering free or discounted roaming. For example, if you’re in the US on T-Mobile, free international roaming is included with “ONE”, “Simple Choice”, “New Classic” or “Select Choice” plans. Others offer low per-day roaming costs. Sometimes these roaming plans require pre-activation, so check with your mobile company before you travel.

Even if your plan does include international roaming, you might want to check the fine print—or just test performance after you arrive. Some plans are restricted to 2G data speeds (for example T-Mobile is restricted to 128Kb/s!), so getting a UK SIM might still be worth it.

How much data do you need?

As long as you log in to wifi when available, you probably won’t use much more data than you use at home. If you go on a data diet, you might be able to keep yourself to 100Mb/day or less, but personally I like to have a comfortable buffer of data for those situations when you need to know if the last train is leaving from your closest station in the next five minutes.

Will it work in my phone?

All the big carriers in the UK sell “trio SIMs” which means no matter which one you buy, it should fit in your phone. Most modern handsets work on multiple bands, but if you’re unsure, check Will my phone work? to see which providers will work with your handset. Just to make sure, you should insert and activate your SIM in the shop where you bought it to check.

Uk sim london
Photo by Gregory Lane

PAYG UK SIM card options

The UK has plenty of mobile carriers and a healthily competitive market, which means you can get a pretty good pay as you go deal. In addition to those listed below, there are also plenty of “MVNO” networks, which piggyback on the bigger networks—such as Virgin Mobile and giffgaff. At least until the UK Brexits (and hopefully afterwards), you also get the benefit of European roaming regulations which came into effect on June 15th, 2017—so you can usually use your UK SIM with no additional charges throughout the remaining 27 member nations of the EU.

Here’s a non-exhaustive list of your PAYG UK SIM card options. Consider it a quick overview.

Note: Three and—if you’re under 30 and in the UK for a while—VOXI are strong contenders for the prime spot, and often have special offers. VOXI offers a contract-free, rolling monthly deal with “endless social data”, allowing unlimited use of social apps without touching your data. It’s a sub-network of Vodafone aimed at younger millennials.

Provider Data/Price Talk(min)/Texts Period Link
6GB £10.00 Unlimited/Unlimited 30 days More info
15GB: £15.00 Unlimited/Unlimited 30 days
45GB: £20.00 Unlimited/Unlimited 30 days

1GB: £10.00 3,000 30 days More info
12GB: £20.00 3,000 30 days
Unlimited: £35.00 3,000 30 days

2GB: £10.00 500/5000 30 days More info
5GB: £15.00 1000/5000 30 days
8GB: £20.00 2000/5000 30 days
10GB: £25.00 3000/5000 30 days
20GB: £30.00 5000/5000 30 days

2GB: £10.00 100/Unlimited 30 days More info
5GB: £15.00 500/Unlimited 30 days
8GB: £25.00 2000/Unlimited 30 days

100MB: £5.00 150/250 30 days More info
6GB: £10.00 250/Unlimited 30 days
12GB: £20.00 1000/Unlimited 30 days
24GB: £30.00 3000/Unlimited 30 days

3GB: £10.00 500/5000 30 days More info
6GB: £15.00 1000/5000 30 days
8GB: £20.00 2000/5000 30 days

Note: Some of these packages may allow for data rollover.

While we do our best to make sure the information in this post is correct, prices and other bits and bobs are subject to change.

This post was originally published on July 12, 2017. Last updated September 6, 2018.

Written by:
Filed under: Technology
Tags: Cell Phone, Data, Getting Connected, Internet, Mobile, Sim Card, Smartphones
London Cheapo small logo


Get all the info on what's on in London direct to your inbox.