Postbag 02

Why does O2 crawl at six o'clock?

Answered 9 July 2026 · reading time about 3 minutes

“My phone shows full bars on my way home but nothing loads until I'm indoors. Is O2 throttling me, or is my handset dying?”

— T.O., Croydon

Man checking his smartphone at an office desk — Photo from a free stock library, used for illustration only.

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The short answerYou are not imagining it. Independent measurement has recorded slower evening data on O2 in busy urban centres for years. It is a crowding problem rather than a coverage one — and it is the single thing to test before you sign anything with O2, Tesco Mobile, giffgaff or Sky Mobile, because all four ride the same masts.

Let's start with why so many people are affected. O2 is the market's biggest landlord: Tesco Mobile, giffgaff and Sky Mobile all broadcast on its masts. The brand itself grew out of BT's Cellnet, took the O2 name in 2002, and has been half of Virgin Media O2 since 2021. It was also the last of the four to retire 3G, finishing during 2025.

What you are seeing at six in the evening is thousands of handsets sharing one mast at the moment everybody gets home or leaves work. Full bars mean your phone can hear the mast perfectly well; they say nothing about how many other people are talking at the same time.

What that means for different people

Situation one

If you commute at rush hour

This is the group the pattern hits hardest. Before signing anything, stand on your own platform at six o'clock with a trial SIM (giffgaff or Tesco, both on O2's masts) and try a video call and a large download.

If it holds up, the rest of O2's package is genuinely good value. If it doesn't, look at EE or Three for that specific postcode — no perk makes up for a stalled commute.

Situation two

If you travel to Europe

Then O2 goes straight to the top of your shortlist. It is the only big-four network still including EU roaming on standard plans, under a fair-use ceiling — historically around the 25GB mark, with O2's own pages carrying the current figure. Beyond Europe, daily travel passes are switched on in MyO2.

Situation three

If you're buying a handset

O2's split contract is the most consumer-friendly structure in the market. The handset and the airtime sit on two separate agreements, and the device half simply stops when the phone is repaid.

You can settle the device balance early and keep only the airtime.
Once the device clears, the airtime is downgradeable.
Both halves are visible on the bill, which makes the arithmetic unusually easy to audit — if you read both lines.

Situation four

If you like perks

Priority is a separate app offering presales, freebies and weekly offers, and it is genuinely enjoyable. Treat it as a tiebreaker between two acceptable options, never as a reason to accept one bar in your kitchen.

Situation five

If you want broadband from the same family

That means Virgin Media — cable and expanding full fibre. It is a wires question, entirely separate from your mobile bars: whether your street is cabled has nothing to do with whether your bedroom gets signal.

Households pairing Virgin broadband with O2 mobile keep being offered bonus data or discounts, so price the pair rather than the parts.

Situation six

If you live somewhere rural

O2 has been running Starlink-partnered satellite messaging trials through 2025–26, aimed at exactly the not-spots where nothing else reaches. They are network-run and free.

Reader beware: Because those trials are real, a scam has grown up beside them. There is no such thing as a “satellite activation fee”. Anyone asking you to pay to enable satellite messaging is defrauding you.

The bits everybody asks about

eSIMIssued through MyO2, the website or shops in minutes, with broad flagship support. PAC to 65075 moves numbers in and out; digital and plastic are identical in law.

Two apps, one loginMyO2 runs the account, Priority runs the perks, and they share a login — which is exactly what 'free Priority reward' phishing hunts. Real offers appear inside the account.

UnlimitedHonest on the handset at home; hotspot-heavy tiers carry tethering clauses, and fair-use ceilings apply abroad.

Price risesPounds-and-pence disclosure before signature, mandatory since January 2025.

LeavingPAC to 65075; the reply itemises the airtime term charge and any device balance before you commit.

Tenant confusionTesco, giffgaff and Sky customers must ring their own brand. The masts are shared; the accounts are not.

Why signal fails on O2

Evening slowdowns in city centres — the documented one, and the reason for this postbag.

Sudden local outages — mast maintenance; status page and postcode first.

Older handsets failing calls — 3G retired in 2025; enable 4G Calling.

One permanently dead room — building materials; Wi-Fi Calling.

Anything on a tenant brand — same masts, same symptoms, different helpline.

The verdict

O2 earns its place on roaming, on contract structure and on perks, and it loses marks on peak-time speed. Average speeds often trail Three and EE. If your evenings pass the test, it is one of the better-value packages in Britain; if they don't, no amount of free coffee fixes it.

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