SIM plans
The four shapes sold in the United Kingdom, how to size an allowance from evidence, and the free protections almost nobody uses.
Buy rolling wherever anything is unproven, size the allowance from three months of your own usage, and switch the free spend cap on the day it activates.
§1The four shapes
| Shape | Who it suits |
|---|---|
| One month, rolling | Anyone with an unproven address, an untested network, or a move in prospect. Slightly dearer; cancel whenever. |
| Twelve or twenty-four months | Settled signal, settled address. Cheaper monthly; the exit position is disclosed on request. |
| Unlimited | Genuinely heavy users, subject to the qualifications in section 2. |
| Pay as you go | Irregular use, spare handsets and testing — covered separately in note AN-10. |
Extra lines under one account attract per-line reductions, so a household should be priced as a whole rather than line by line.
If any of this is unclear
Telephone the advisory and we will talk it through. There is nothing to buy at any point.
§2Where unlimited is qualified
On the handset, at home, unlimited is genuinely unmetered on all four owners. Three things bend it, and all three are findable before you sign.
- Tethering. Capped on some plan generations despite the headline — the clause that matters if you work from a laptop.
- Network management. Extreme outliers can be briefly queued at saturated masts; ordinary heavy use never notices.
- Abroad. A fair-use ceiling applies everywhere, after which per-gigabyte charging begins. Nothing survives the border unlimited.
§3Sizing the allowance
Every provider's app records what you actually used. Three months captures a real pattern including holidays and unusual weeks.
Buy that measured average with modest headroom. The recorded gap between what people estimate and what they consume is commonly around double — which across a two-year term is a substantial sum.
Two free adjustments usually remove the need for a bigger allowance entirely: drop video quality one step inside the streaming app, and restrict backups and app updates to your home broadband.
§4The free protections
| Protection | What it does |
|---|---|
| Spend cap | Prevents charges beyond the allowance. Free, about a minute in the app, and rarely enabled. |
| Price-rise disclosure | Since January 2025, any mid-contract increase must be stated in pounds and pence before you sign. |
| Exit itemisation | Any early-termination charge is disclosed before you commit to leaving. |
| The annual review | Ten minutes a year against three rivals on the same allowance beats any promotional event. |
§5Steps to take
Speak to the advisory
Telephone the advisory and we will talk it through. There is nothing to buy at any point.