Three Mobile Discount Codes & Deals for 2025

1. Copy a Three Mobile voucher code from us and follow our link to the homepage.
2. Explore online and select the mobile plan you want, and add it to your basket.
3. Once you're finished shopping, you can head to the checkout.
4. Here you can paste your copied discount code and continue to pay.

Three Mobile is one of the best networks for getting the latest handsets without spending a fortune. Their contracts, SIM Only plans and Pay As You Go deals are all competitively priced, with extras like half-price plans for the first 12 months and trade-in savings of up to £400 making them even better value.

When I upgraded to the iPhone 16 Pro Plus, I combined a seasonal sale with a Three Mobile discount code and managed to save about £25 off my monthly plan - that’s almost £300 saved over the year.

I also like the peace of mind with Three’s unlimited data plans, as it means no surprise bills at the end of the month! Their refurbished phones are another clever way to save if you want a newer model without the hefty price tag.

Add in little extras like the Three+ rewards app, free roaming in certain countries and simple upgrade options, and it’s easy to see why I stick with them - it just feels like you get more for your money.

Download the Three+ App

If you’re already a Three customer, the Three+ app is worth downloading! There are loads of little perks on there to help you save money.

• You can grab £1 coffees at Caffè Nero and cheaper cinema tickets at Cineworld!
• Find discounts on food, fashion and entertainment from well-known brands.
• New offers appear often, so it’s handy to check in every week.

Look at the Latest Offers Before You Buy

Three’s website has an offers page ^↗ that’s regularly updated! It’s the first place we’d suggest you check before signing up for a new plan.

• Here you'll spot reduced prices on SIM-only deals and monthly contracts.
• Find trade-in savings worth up to £400 when swapping an old handset.
• Browse refurbished phones if you want a newer model at a lower cost.

Switch to SIM Only or Data Packs

If your current phone still does the job, switching to a SIM-only deal can save a big chunk of money each month!

• SIM-only plans start at around £11 for students, or £13.50 for 120GB with unlimited calls and texts.
• You can get 6 Months Half Price on selected SIM-Only deals.
• Pay As You Go Data Packs are flexible and avoid long-term contracts.
• Dropping the handset cost can cut your bill by half!

Use Student Discounts

Students can get lower rates on the three plans with a verified student email.

• Save 20% on airtime across selected SIM-Only and contract deals.
• Stack this with seasonal sales for an even better value.
• Easy to set up online in just a few minutes.

Link Plans for Household Savings

If more than one person in your home uses Three, there are savings to be had by linking plans.

• Add extra lines to your account and get up to 20% off additional plans.
• Works for broadband as well as phone contracts.
• Keeps billing simple with everything under one account.

Trade In or Buy Refurbished

Upgrading doesn’t always mean paying full price for a brand-new phone.

• Trade in your current device for money off a new handset - some models give you up to £400 back.
• Consider refurbished phones, which cost less but still come with warranty cover.
• Both options are great ways to get a high-end device without the premium price tag.

Use the Coverage Checker Before You Sign Up

Want to make sure you’ll get a good signal before switching? Three’s online coverage checker makes it simple.

• Enter your postcode to see the strength of 3G, 4G and 5G in your area.
• Register for updates so you’ll know if coverage improves where you live or work.
• It’s a quick way to avoid paying for a plan that won’t give you the service you need.

Switching to Three is Quick and Easy

Moving your number over to Three only takes a text message and means you don’t have to start from scratch with a new number.

• Request a PAC (Port Authorisation Code) from your current network.
• Give this to Three when you set up your plan - they’ll handle the rest.
• Your old provider is responsible for closing your account, so you don’t need to worry about chasing them up.

Three has a wide choice of deals, whether you want the newest iPhone, a simple SIM plan or a Pay As You Go option. The trick is knowing where to look and how to make your money go further! Here’s what to keep in mind when shopping with Three.

Pay Monthly Phones - Spread the Cost of the Latest Handsets

If you like upgrading to the latest phone, Three’s Pay Monthly contracts are the easiest way to do it without paying the full cost upfront.

• Three stocks all of the big names, including the iPhone 17 series, Samsung Galaxy S25 range, and the latest Google Pixel 9.
• Keep an eye on their Latest Offers page - you’ll often find half-price plans for the first year or trade-in deals worth up to £400.
• Don’t overlook refurbished phones. They’re usually hundreds cheaper than buying new and still come with warranty cover.
• If you can afford to, paying a bit more upfront will bring down your monthly bill, which can save you a fair bit over a 24-month plan.

Choose a SIM Only Plan

If you're happy with the phone you've got, switching to SIM-Only is one of the quickest ways to cut your costs.

• Plans start from around £11 a month for students or £13.50 for 120GB data with unlimited calls and texts.
• Unlimited data plans are still a good value compared to other networks, especially if you stream a lot.
• Longer contracts (12 or 24 months) usually work out cheaper per month than rolling 30-day options, so it’s worth weighing up how much flexibility you really need.
• Three currently has fantastic deals like 6 months half price on selected 24-month plans, so it's worth exploring your options. These deals, paired with a Three Mobile promo code, could be key to grabbing a great saving!

Keep it Flexible with Pay As You Go

If you don’t want to be tied into a contract, PAYG is a simple alternative.

• Three’s Data Packs bundle minutes, texts and data for a set monthly price - no contract needed.
• Great if you want full control of your spending or need a temporary plan.
• Top up online or in the app and just renew when you need to.