Is Three's cheap data a trap?

If you work from home all week

This is where Three has to prove itself. Its weakness has always been deep indoors — back rooms, basements, thick-walled Victorian houses — and no price makes up for a dropped client call.

• Buy a one-month SMARTY SIM (identical masts, pocket money) before anything else.
• Switch Wi-Fi Calling on immediately; it routes calls through your broadband and makes walls irrelevant.
• Test the actual room you work in, not the doorstep.

If you commute into a city

Three is at its best here. Independent testing repeatedly puts its 5G speeds at or near the top of the market, and city masts are its home ground.

Test at your own station at rush hour anyway — congestion is invisible on every coverage map ever published, and full bars with frozen data is a crowd problem rather than a coverage one.

If you use a lot of data

This is the whole reason to look at Three. It has priced unlimited lowest of the four mast owners year after year. Two clauses matter before you sign:

• Tethering. Some plan generations cap hotspot use even on unlimited. If you share data with a laptop, read this line first.
• Abroad. A fair-use ceiling applies everywhere overseas, then per-gigabyte charges. Nothing survives the border unlimited.

On the handset, at home, unlimited genuinely means unlimited — there is no meter to watch.

If you travel to Europe often

Then Three is probably the wrong shortlist. Most newer plans meter Europe with a daily fee, although some older plans kept inclusive roaming — your plan's start date decides, and the app's roaming screen is the referee.

If you stay with Three, the fix is dual-SIM: keep the Three line for calls and add a cheap local data eSIM at your destination. Past a few days that comfortably beats daily fees.

If you need home broadband too

Three's home broadband is the mobile network in a box — a 4G/5G router in the post, live the day it lands, no engineer and no line rental. When the local mast is strong and quiet it embarrasses mid-price fibre.

When it isn't, evenings crawl and nothing inside the house fixes it. Treat the returns window as a paid trial: put the router at the window facing the mast, hammer it for a full week of evenings, and send it back free if it fails.

If you want a handset on contract

Three sells the standard bundle — phone plus airtime over 24 to 36 months. The trap is the end of the term, when the bill does not fall by itself and you carry on paying handset money for a phone you already own.

• Diary the end date the day you sign.
• Benchmark every bundle against the phone bought outright plus the cheapest good SIM.
• Take a second trade-in quote before accepting any number at the till.