Best Pay As You Go SIM deals: The best cheap deals, roaming deals and unlimited data deals from £5/month

Don’t fancy a monthly contract on your mobile? A pay-as-you-go SIM could be the answer. If you’re a light user, for instance, it may work out cheaper than a regular contract. Or, you might simply be uncomfortable about committing to an 18-month or 24-month contract, and prefer the flexibility of being able to switch deal, month by month. For many people, PAYG makes a lot of sense - but with so many different plans and providers out there, which one should you pick? Here’s our guide to the best deals.

Looking for a SIM-only contract instead? Then check out our guide to the best deals here

How to choose the best Pay As You Go SIM deal for you

It’s not uncommon to get a PAYG SIM bundled with a new handset, but there are any number of replacement SIMs you can choose to use instead. These tend to come free from the network provider, or very cheaply from from a local supermarket or newsagent. Once you’ve installed the SIM, you can generally top it up with credit from your phone using vouchers, or directly from a shop or a cashpoint.

What differentiates the various SIMs on offer is how this credit gets used. Most networks have a base tariff, setting out the standard cost of making calls, using data or sending texts, with additional charges for calling premium numbers, using premium SMS services, retrieving answerphone messages or using your phone abroad. However, you can normally get better value by buying “bundles” of services, whereby you pay a fixed fee for a package of call, data and text allowances.

How much data do you need?

Bundles normally range from £5 to £20, and naturally the more you spend, the more calls, texts and data you get. Beyond the £10 mark you’re typically looking at a big chunk of call time (500 minutes or more) and unlimited texts. Data allowances can vary significantly, however, so it’s a good idea to work out how much you need.

If you spend almost all of your time connected to a home or office Wi-Fi network then 1GB of mobile data could easily last you a month. However, if you’re a heavy user of social media or make lots of video calls then your usage will go up a lot - and that’s without streaming video or music.

Some networks, including EE, GiffGaff, O2 and Vodafone, also allow you to use your data allowance for tethering - that is, connecting a laptop or tablet to the internet through your smartphone - which can eat up data very quickly. And once you’ve exhausted your bundle, the cost of data tends to rocket, typically to 5p per megabyte.

Remember, though: while it’s important to buy enough data, there’s also no point spending money on a huge allowance you won’t use, especially as not all networks allow you to roll any unused data over to the next month. The beauty of PAYG is that you can stick to a low-data bundle for most of the year, then switch to a high-data bundle as needed - for example, when you’re going away on holiday.

Do I need to worry about speed or network coverage?

A SIM deal that looks like great value isn’t much use if the connection is slow or flaky - and speeds and coverage vary massively from network to network and location to location. The smaller operators normally piggyback on one of the major mobile networks, and every one has a coverage checker, so it’s worth using this to check what speeds you can get in your immediate area. It’s also worth asking friends who live nearby which networks have and haven’t worked for them.

Another good, and entirely independent, option is Rootmetrics’ coverage map which can help you pinpoint both coverage and speeds in your area. Click here and have a look before you grab a new PAYG SIM. 

What about making international calls or going abroad?

If you have friends and family overseas, then definitely investigate how much it costs to make international calls. Many providers offer cheap calls to specific destinations, but (for example) the SIM that’s cheapest for calling the USA might be expensive for calling Brazil, and vice versa. In some cases, paying for an add-on can slash call costs.

It’s also a good idea to do some homework if you’re planning to take your own phone abroad. Within the EU you should be able to use your phone on exactly the same terms as within the UK, although it remains to be seen whether that will still be true after Brexit.
Outside of the EU, things can be much more expensive. Some networks offer lower charges or free usage in specific territories, or add-ons that can cut the cost. Alternatively, it might make sense to buy a local PAYG SIM rather than roaming on your UK SIM.

Read more: Check out the best budget smartphones to buy in 2017

The best Pay As You Go SIMs and deals from £5

1. 1pMobile: The best PAYG SIM for light users on a tight budget

1p per minute, 1p per text, 1p per MB

1p’s proposition is as straightforward as it gets, and if you only make light use of your phone it’s terrifically cost-effective. You pay £10 for the SIM, which includes your first £10 of credit and, as the name suggests, all your basic requirements cost a penny from there on in. If you use less than 500MB of data a month, you should save money compared to rival networks – and if you need more data, competitively priced data boosts give you 500MB for just £4, or a whole gigabyte for a mere £6. What’s more, credit rolls over with no expiry period, provided you top up at least every 120 days, so your £5 or £10 could stretch a very long way. Charges are higher for premium numbers and text services, and costs also rise significantly while abroad – but with tethering bundled in, 1p is a tempting option even for those that need more calls or data. 

2. GiffGaff £10 and £12 Goody Bags: The best PAYG deals for moderate users

£10 for 3GB/500 minutes/unlimited texts or £12 for 4GB/750 minutes/unlimited texts

GiffGaff is owned by the same company as O2, and it operates on the same network - but its PAYG pricing is much more attractive. While the base tariff isn’t particularly cheap, even the entry-level £7.50 Goody Bag will net you 1GB of data, 250 minutes and unlimited texts – and the £10 and £12 bundles take that up to 3GB and 500 minutes, or 4GB and 750 minutes respectively. GiffGaff also allows tethering and offers pretty good pricing on international calls, at between 2p and 5p per minute. It’s not as flexible as other providers though: bundles expire after a month, and there’s no rollover. Its community-driven approach to support and troubleshooting doesn’t always mean a great customer service experience either. Still, at the price it’s hard to complain.

3. Three: Best for heavy users and travellers

£10 for 1GB data/3,000 minutes/3,000 texts

Of the major networks, Three is the most competitive when it comes to call and data allowances. Its base tariff undercuts the likes of EE, O2 and Vodafone, and its mid-range and high-end bundles are particularly good value. £15 gets you 5GB of data, 3,000 minutes and 3,000 texts, while another £5 ups your data allowance to 12GB. It’s a shame that Three doesn’t allow tethering on PAYG, although credit for unused data does roll over into the next month. Three is also a good choice for roaming: its Feel at Home feature allows you to use your allowance not just within the EU but in over 60 countries worldwide, including Australia, Brazil, Singapore and the US.

4. O2 International Sim: The best PAYG SIM for international calls

£10 for £10 international call credit/3,000 O2 texts/100MB data; £15+ for £15+ international call credit/3,000 O2 minutes/3,000 O2 texts/200MB data

O2’s standard £10 PAYG SIM includes 2GB of data, which is a good deal – and it allows tethering too, which almost makes up for the fact that unused data doesn’t roll over at the end of the month. O2’s real strength, though, is its international bundles. These let you stay in touch with a wide range of countries at very low prices: for instance, it’s just 2p per minute to call US mobiles and landlines, 3p per per minute to call South African landlines and 3p per minute to call Brazil. The catch is that UK calls are expensive, and data usage outside the tiny 100MB to 200MB bundled allowance is astronomically pricey – so it makes sense to buy a second SIM for everyday use and save this one for international calls.

5. Three All-You-Can-Eat: The best unlimited data deal

£35/month for unlimited data

Three’s £35 All-You-Can-Eat option isn’t the cheapest unlimited PAYG deal – that’s GiffGaff’s £20 Goody Bag. But with GiffGaff, only your first 9GB of data is served at full 4G speeds. after which you’re reduced to 384Kbits/sec between the hours of 8am and midnight. Three’s deal is nearly twice as expensive, but gives you unlimited data at full 4G speeds, subject to Three’s TrafficSense traffic management. You can’t tether it to a tablet or laptop, but if you need serious amounts of data in the palm of your hand, Three’s offer is the best in town.