What to check before you choose.
Terms vary by plan, date and eligibility. This guide explains how to evaluate Three without pretending to quote a live tariff. Verify exact prices, annual increases and availability on the operator’s current documents before agreeing.
Three: what it is
Three’s UK mobile service began in 2003 with 3G. It now offers SIM, handset and pay as you go services. Its network is part of the VodafoneThree group following the merger. It is worth separating the brand that bills you from the radio network beneath it. Look at the current coverage map for your postcode and whether indoor coverage in your usual buildings meets your needs.
SIM only, monthly & pay as you go
A SIM-only plan uses a phone you already own. A monthly plan may carry a minimum term; an ongoing or prepaid bundle renews on its own schedule. Pay as you go data packs differ from a monthly airtime contract. Before buying, note the allowance, promotion end date, recurring charge, out-of-bundle rate and cancellation route.
Phone contracts & upgrades
Three Your Way separates phone and airtime options; compare the total over the term. For an upgrade, request the remaining handset balance and the new total payable rather than comparing only the headline monthly figure. Your current contract and any trade-in condition can change the maths.
eSIM & activation
Check My3 and the Three app for eligible eSIM conversion or replacement. First check that your model supports eSIM, that it is unlocked where required and that this specific plan accepts eSIM. Keep Wi-Fi available during activation. Do not delete an existing profile until the replacement is working; a QR code may be single-use.
Verify on the official eSIM help page ↗.
Coverage, 4G, 5G & signal
Three coverage is location-dependent. Enter your full postcode into its official checker and test indoors, at your commute stops and at busy times. A coverage map predicts service outdoors; it is not a guarantee inside a building. Restarting the handset, checking airplane mode and updating network settings are sensible first checks.
Data & “unlimited”
Use your bill or My3 / Three app to see actual monthly usage before choosing a data tier. “Unlimited” can still have fair-use, tethering, speed-management or roaming restrictions under the tariff. Compare your home, work and travel use, and read the full terms of the exact offer.
Roaming & international use
Go Roam rules depend on the plan and destination; check the allowance and daily charge. Check destination, daily charge, data cap, fair-use allowance, calling rate and whether an add-on activates automatically. International calling from the UK is a different charge from roaming abroad. Download the rate table before travelling.
Broadband & mobile data
Three also markets home broadband; test indoor signal and terms before substituting it for fixed line. A mobile signal or hotspot is not identical to fibre: latency, capacity, indoor reception and data policy all matter. If ordering any home internet product, check address availability and its own contract and cancellation terms.
PAC code, STAC & switching
To keep your number, text PAC to 65075 from the number you intend to move. If you do not want to keep the number, text STAC to 75075. Give the code to your new provider. Ofcom explains the switching process; the old provider may tell you about outstanding handset charges. brockwatt cannot issue a code or move a number.
Account app & self-service
My3 / Three app is the usual place to inspect usage, bills and eligible account changes. Use the official app-store listing or the provider website; do not give anyone your login, one-time passcode or payment card on an unsolicited call. App access and features can differ by PAYG or contract type.
Monthly cost, annual rises & fees
Write down the starting monthly price, the post-promotion price, the minimum term, annual increase date and any handset balance. A 12-month comparison is 12 × the applicable monthly service charges plus one-off fees and expected extras; a full contract comparison must include later price changes and device repayments. Current pounds-and-pence pricing depends on your personalised offer and changes over time.
When things stop working
For no signal, check the local outage page, restart, disable airplane mode, reseat a physical SIM or confirm the eSIM is active. For slow data, compare another place and time, inspect your allowance, then reset network settings only after noting saved Wi-Fi details. Record dates and screenshots; use Three official support for account-specific repair or a complaint.
Read the original terms.
These official pages are the starting point for current details. Public information changes; our explanation is editorial guidance, reviewed September 2026.
Three eSIM / help ↗Three plan / travel help ↗Ofcom switching guide ↗