SMARTY’s £16 Unlimited Data SIM: No Contract & 5G Coverage From Three

SMARTY is offering a £16 unlimited data SIM card in May 2025. There’s no contract, no credit check & 5G coverage from Three.

In the UK, SMARTY Mobile is currently offering an unlimited data SIM card for only £16 per month. It’s a special offer for new customers that sign up in May 2025, and it is reduced from their normal price of £20 per month.

To get the £4 per month discount, you’ll need to order through this special link. The plan gives you unlimited UK minutes, unlimited UK texts, and unlimited data for £16 per month. It’s a one-month rolling plan, with no contract and no need for a credit check. You’ll get 4G & 5G coverage from the Three network.

Get unlimited data for £16 on SMARTY →

In this article, we’ll review SMARTY’s unlimited data SIM card. We’ll start by looking at what their £16 unlimited data SIM card includes, along with the download speeds available and the fair usage policy. We’ll also look at how SMARTY’s unlimited data plan compares to other networks, and how you can keep your current phone number when you move to this deal.

Exclusive Deal:	Unlimited data for £16 (no contract)
Reasons To Buy:	SMARTY’s £16 unlimited data SIM is one of the cheapest in the market. You’ll get the fastest available speeds on Three, with no fair use limit. Use your plan at no extra cost in the EU (up to 12GB per month). No annual price rises: the cost is fixed at £16 per month for 15 months.
Reasons To Avoid:	The £16 deal is only available to new customers who order through this link. SMARTY’s coverage is limited in areas where Three has poor coverage. There’s no support for Pay As You Go eSIMs at present.
Coverage:	Three coverage (4G & 5G) – check postcode

SMARTY’s £16 Unlimited Data SIM

In the UK, SMARTY is a low-cost mobile network that’s owned and operated by Three. All of their SIM cards work on a one-month rolling basis, and customers can join SMARTY Mobile with no contract and no need for a credit check.

SMARTY’s flagship plan is their unlimited data SIM card.  It’s normally priced at £20 per month, but there’s a special £4 per month discount (valid for 15 months) when you order through this link. This brings the price of your unlimited data SIM card down to £16 per month:

Network	Data	Monthly Cost
Three coverage Unlimited mins Unlimited texts	Unlimited data	£16.00 per month 1 month rolling	See deal

On this £16 unlimited data deal, you’ll get all of the following features included:

• Unlimited data with no fair use limits. There are no hidden fair usage limits on SMARTY’s unlimited data plan, so long as it is being used only “for your personal and non-commercial use”. Prior to 2020, there was a 1,000GB per month threshold that was used to identify possible commercial use of the service. However, SMARTY have said that this is no longer being used.
• 4G & 5G coverage from Three, with the fastest available speeds. With this plan, you’ll get the fastest available download speeds on Three’s network, without any throttling or speed restrictions. If you’re SMARTY in a 5G area, the average download speed should be around 236Mbps.
• Roam at no extra cost in the EU (up to 12GB per month). You’ll be able to use SMARTY’s unlimited data plan at no extra cost when you’re abroad in 42 EU destinations. This includes your unlimited minutes, texts and data (up to 12GB per month).
• Unlimited UK minutes, texts and MMS. Alongside your unlimited data allowance, you’ll get unlimited UK minutes, unlimited UK texts, and unlimited UK picture messages (MMS).
• Tethering, personal hotspot & mobile broadband. On SMARTY, you’ll be able to use your unlimited data allowance for tethering, personal hotspot and mobile broadband. This is confirmed on the SMARTY website. For this reason, many people use their plans as a backup or as an alternative for home broadband.

It’s also possible to get a data-only version of SMARTY’s unlimited data plan. For all intents and purposes, this is identical to the £16 unlimited data plan, but you won’t get the unlimited UK minutes and texts. As the data-only plan currently retails for £20 per month, there are very few good reasons to choose it at the moment (as you can use the regular £16 plan with no obligation to use the minutes and texts).

If you’re planning to use a SMARTY SIM card for 4G or 5G home broadband, one limitation is that you won’t get a publicly-accessible IP address on it. This is because SMARTY uses strict CGNAT technology, giving you a private IP address that’s unable to accept incoming connections. It doesn’t affect most online activities, but it can stop you from doing things like running a server, using certain P2P apps or playing some online multiplayer games.

Alternatives

If you’re looking for an alternative to SMARTY’s unlimited data plan, it’s also possible to get unlimited data on Talkmobile for £16 per month. This is a one-month rolling plan with access to Vodafone’s 4G and 5G network.

Talkmobile is the low-cost sub-brand of Vodafone, much like SMARTY is the low-cost sub-brand of Three.

Network	Data	Monthly Cost
Vodafone coverage Unlimited mins Unlimited texts	Unlimited data	£16.00 per month 1 month contract	See deal

If you’re living in an area where there is poor coverage from SMARTY/Three, this could be a good alternative.

For more information, see our guide to the best unlimited data plans in the UK.

Network & Coverage

On SMARTY’s unlimited data plan, you’ll get 4G & 5G coverage from Three’s mobile network in the UK. At the time of writing, this equates to 99.8% population coverage on 4G. There’s also 60% population coverage on 5G.

You can check the coverage in your area by entering your postcode on SMARTY’s online coverage map:

Check SMARTY Coverage Map (smarty.co.uk) →

You’ll also have access to 4G Calling and Wi-Fi Calling if you have a compatible device on SMARTY.

For more information, see our guide to SMARTY’s network and coverage.

Keeping Your Phone Number

If you’d like to keep your current phone number when you join SMARTY Mobile, it’s a straightforward process to transfer it from your old mobile network.

Start by ordering your unlimited data SIM card from SMARTY’s website. To begin with, it will come with a temporary phone number assigned to it, allowing you to test out the service before moving your phone number over.

When you’re happy to move your phone number over, you’ll need to get a PAC Code from your old network. This is available through your mobile network’s website or app, or by texting PAC to 65075. You can then submit the PAC Code to SMARTY through your online dashboard. Once you’ve done that, your phone number transfer will normally take place on the next working day.

For step-by-step instructions on how to move your phone number to SMARTY, please select your current mobile network from the drop-down menu below:

For more information on transferring your phone number between networks, see our guide to using a PAC Code.

More Information

For more information on SMARTY’s unlimited data plan, please see their official website.