By giffgaff’s Data Boost SIM-only plans now come with up to 200% more data. Deals include 75GB for £10, 150GB for £12, and 300GB for £15.
If you’re looking for a new SIM-only plan that gives you lots of data, giffgaff is currently offering ‘data boost’ SIMs such as 75GB data for £10, 150GB data for £12, and 300GB data for £15. These deals are available on an 18-month contract. There are also one-month rolling ‘data boost’ plans available to buy.
All of giffgaff’s data boost plans come with built-in flexibility, allowing you to change your plan over time. There’s also no credit check needed to sign up, plus inclusive EU roaming (up to 5GB per month).
In this article, we’ll look at giffgaff’s data boost offers which are available until the 18th May 2026. We’ll also look at the key features included on their plans and how you can keep your current phone number when you move to giffgaff.
| 18 Month Plans†: | |
|---|---|
| 1 Month Rolling Plans†: |
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| Key Features: |
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| Offers End: | 18th May 2026 |
| Coverage: | O2 coverage (4G & 5G) – check postcode |
† Plan must be activated between 2/2/26 and 18/5/26 to qualify. Eligibility criteria, terms and exclusions apply, see giffgaff.com/terms/promotions.
†† Data roaming in EU and selected destinations is capped at 5GB. You’ll be charged 10p/MB once 5GB is used if no add-on is applied.
giffgaff Data Boost Plans
As a special offer until the 18th May 2026, giffgaff has enhanced some of their SIM-only plans with extra data. You can choose between their 18-month contracts (which give you the best value), or their one-month rolling plans (if you need more flexibility).
18 Month Deals
At the moment, you can get triple data on giffgaff’s £10, £12 and £15 plans when you sign-up on an 18-month contract. This makes it possible to get 75GB data for £10, 150GB data for £12, or 300GB data for £15.
Although it’s an 18-month contract, these deals work a little differently to the contracts that you’ll find on many other providers. That’s because there’s built-in flexibility so you can change your plan over time, as long as you stay within giffgaff’s 18-month range. For instance, you can increase or decrease your data allowance, without resetting the term of your commitment.
There’s no credit check needed when you sign up for these deals. Also, there are no mid-contract price rises on an 18 month contract, when you sign up before the end of 2026 (fair usage policy & terms and exclusions apply, see giffgaff.com/terms):
| Plan | Data | Monthly Cost | |
|---|---|---|---|
Offer ends 18th May | 75GB data | £10.00 per month 18 month contract | See deal |
Offer ends 18th May | 150GB data | £12.00 per month 18 month contract | See deal |
Offer ends 18th May | 300GB data | £15.00 per month 18 month contract | See deal |
1 Month Rolling Deals
If you need even more flexibility, you can choose a one-month rolling ‘data boost’ plan from giffgaff instead. For instance, there’s currently 40GB data for £10 (increased from 20GB) or 75GB data for £12 (increased from 26GB). On these one-month rolling plans, you’ll receive the extra data for 6 months.
| Plan | Data | Monthly Cost | |
|---|---|---|---|
Offer ends 18th May | 40GB data | £10.00 per month 1 month rolling | See deal |
Offer ends 18th May | 75GB data | £12.00 per month 1 month rolling | See deal |
Offer ends 18th May | 150GB data | £15.00 per month 1 month rolling | See deal |
Offer ends 18th May | 300GB data | £20.00 per month 1 month rolling | See deal |
As before, there’s no credit check needed when you sign up for these deals. You can also change your plan from month-to-month as you need.
What’s Included?
Flexible Plans
On all of giffgaff’s SIM-only plans, you have the option to change your plan over time. This can be useful, for instance, if you’d like to move to a plan with more data. Alternatively, you can move downwards to a cheaper plan to save some money.
If you’re on an 18-month plan, you’ll be able to move upwards or downwards to any other plan within giffgaff’s 18-month range. When you do this, it won’t reset the term of your commitment and you won’t incur any early termination fees for changing your plan.
If you’re on a one-month rolling plan, you’ll be able to change to any other plan within giffgaff’s range, whenever you like. This will take effect on your next plan renewal date.
No Credit Check
On giffgaff, there’s no credit check needed when you sign up for a SIM-only plan. This makes it really easy to sign-up, without the need to provide lots of obscure information. It also means their plans are open to everyone, regardless of what your credit rating or credit history looks like.
If you choose to buy a mobile phone from giffgaff, a status and credit check will apply if you choose to take out a payment plan with Klarna. However, there’s no credit check needed if you decide to pay for it in one go.
No Mid-Contract Price Rises
On many other networks, it is common to have an annual price rise built-in to your plan. This can increase the cost of your plan every year by up to £2.50 per month.
For all 18-month contracts purchased before the end of 2026 (fair usage policy & terms and exclusions apply, see giffgaff.com/terms), giffgaff has guaranteed that there’ll be no mid-contract price rises.
If you sign up on a one-month rolling plan, there’s no guarantee. However, on a historical basis, giffgaff has only really made positive changes to their plans (e.g. by increasing the amount of data), with both new and existing giffgaff members benefitting from the change.
Certified B Corp
The ‘B Corp’ movement is a global initiative for businesses that commit to being a force for good. Their member companies make legal commitments to their social and environmental impact, as well as transparency in the way they run their business. This has established it as a key trust mark for consumers seeking an ethical brand.
giffgaff is a certified B Corp with a score of 85.8. This score is based on five main areas: how they treat their customers, colleagues, the community, the environment, and how they run their business.
According to giffgaff, they’ve generated more than £1m worth of charitable donations together with their members. In addition, all of their SIM cards are made from recycled plastic, and dispatched in fully recyclable packaging. In addition, giffgaff offers a choice of refurbished mobile phones, allowing members to save money and to be more sustainable.
4G & 5G Coverage From O2
giffgaff is powered by the O2 network – you’ll get both 4G coverage and 5G coverage included as standard.
Before you sign up to giffgaff, it’s worth checking to make sure you can get coverage where you live. You can do this by entering your postcode on giffgaff’s online coverage map:
Check giffgaff coverage (giffgaff.com) →
5G T&Cs: You need 5G coverage, a 5G device and SIM, and 5G switched on in your giffgaff account. Find out more about 5G coverage see https://www.giffgaff.com/help/articles/does-my-area-have-5g-coverage. Terms apply, see giffgaff.com/terms.
Inclusive EU Roaming
If you’re travelling abroad, you’ll be able to use your giffgaff plan allowances at no extra cost in 37 European destinations. This includes popular tourist hotspots such as Spain, Italy, France, Portugal and more.
If you’re travelling further afield (e.g. to the USA, Australia, China, Hong Kong, India, Turkey, and more), there are a range of travel data add-ons available from giffgaff.
Add-on price varies. Data only, valid for 30 days or until used. No calls/texts. Selected destinations. Via app only. Fair usage policy, data roaming restrictions and terms apply.
giffgaff App & Community
You can use the giffgaff app to manage your account, including seeing how much data you’ve used and what’s left on your plan. It will also give you free access to thousands of Wi-Fi Extra hotspots across the UK.
If you need help and support, this is available through giffgaff’s online community. According to giffgaff, the majority of questions asked in their community will get answered by other giffgaff members within two minutes. For any account-specific queries (e.g. to do with your SIM card or payments), you can ask a giffgaff agent online.
Keeping Your Phone Number
It’s easy keeping your current phone number when you switch to giffgaff.
Start by ordering your new SIM-only plan from giffgaff’s website. Once you’ve done that, you can ask your current mobile network for a PAC Code. This is available through your mobile network’s website or app, or by texting PAC to 65075.
Once you’ve activated your new giffgaff SIM, you’ll be able to submit your PAC Code online through a form on their website. This will schedule the transfer of your phone number (normally for the next working day, as long you submit it before 3pm).
For a step-by-step guide on how to transfer your phone number to giffgaff, please select your current mobile network from the drop-down menu below:
More Information
For more information about the data boost offers, see giffgaff’s official website.
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