Three Discount Code

Three is one of the UK’s largest mobile networks, serving around 10 million customers with a range of 3 deals across SIM-only plans, handset contracts, and home broadband — and BudgetFitter tracks verified Three discount codes and referral offers so you can reduce the cost of switching or upgrading. Whether you’re looking for a Three discount code or a competitive SIM-only deal, the network’s Truly Unlimited Data plans remain one of the strongest value propositions in the UK mobile market.

Three (also written as ‘3’) launched in 2003 as the UK’s first commercial 3G network and has since expanded to cover 5G across major UK cities. Its standout product has long been unlimited data with no throttling — a genuine differentiator compared to many budget alternatives that slow your connection after a threshold. For heavy data users, that distinction matters far more than headline pricing.

What Three Offers UK Customers

Truly Unlimited Data Plans

Three’s SIM-only range is built around Truly Unlimited Data — no data cap, no speed throttling after a set amount. This places it ahead of budget operators that advertise ‘unlimited’ plans with fair-use restrictions buried in the small print. Plans are available on rolling 30-day contracts or longer 12 and 24-month terms, with lower monthly costs rewarding commitment. Three also includes calls and texts as standard across all its plans.

For customers who travel, eligible Three plans include Go Roam — free data roaming in over 70 countries at no extra charge. This is particularly useful for frequent travellers who would otherwise pay daily roaming fees on other networks. Alternatives like giffgaff and SMARTY Mobile run on the Three network infrastructure, so choosing Three directly gives you the same underlying coverage with access to official loyalty perks and customer support.

Handset Deals and Phone Contracts

Three sells the full range of current smartphones — iPhone, Samsung Galaxy (including S-series and foldables), Google Pixel, and others — on pay monthly contracts bundled with a data plan. Trade-in discounts are available for existing devices, and refurbished handsets offer a lower-cost entry point for those who don’t need the latest model. Multi-line account holders can access discounts when adding additional SIMs or handsets to the same account.

Three’s ‘Three Your Way’ upgrade programme lets customers trade in their device and upgrade before the end of the contract period, avoiding the 24-month lock-in that frustrates customers on standard contracts. eSIM support means digital switching without a physical SIM card swap — useful when setting up a new phone quickly or managing a travel SIM alongside a primary contract. If you’re comparing options, the UK Mobile Network Matcher on BudgetFitter lets you find the best-value plan across the major UK networks.

Home Broadband

Three’s home broadband service uses 5G or 4G routers that require no engineer installation — the device arrives pre-configured and connects to Three’s mobile network rather than a fixed line. This makes it a practical option for renters, people in areas underserved by fibre, or anyone who wants broadband without a 12-month fixed-line commitment. Speeds vary depending on local 5G coverage, but in well-served areas the performance is comparable to entry-level fibre packages. For those evaluating fixed-line options, BudgetFitter’s UK Fibre Broadband Deal Finder covers alternative providers.

Three+ Rewards and the Referral Programme

Three+ is the network’s loyalty programme, offering existing customers discounts and perks on entertainment, food, events, and more — updated regularly and accessible through the Three app. It’s a benefit that adds value beyond the core plan without requiring additional spend. Separately, Three runs a referral programme where both the referrer and the new customer receive a reward when a qualifying contract is taken out. BudgetFitter maintains the verified referral offer, which stands at up to £80 — check the deals section above for the live terms. Compared to smaller MVNOs like VOXI Mobile or 1pMobile, Three’s combination of network ownership, unlimited data, and a structured rewards programme makes it a well-rounded choice for customers who want more than just a low monthly bill.