UK eSIMs: what Brexit changed, and what unlimited really costs

Roaming is now a question only your operator can answer

Before Brexit, this section did not need to exist. The UK was inside the EU roaming regime, an EU number worked in London on its home allowance, and a British number worked in Spain the same way.

That is no longer the case. The UK left the EU, so roam-like-at-home does not cover British territory and does not cover British numbers abroad. What replaced it is not a single rule but a patchwork of individual commercial decisions: some operators on both sides kept the UK or the EU inside their home-tariff zone voluntarily, and others reintroduced charges. Several have changed their position more than once since.

We are not going to guess which category yours falls into, because getting it wrong in either direction is expensive. If we tell you that you are covered and you are not, you get a bill. If we tell you that you are not and you are, you buy a plan you did not need. The honest answer is that this is written in your own tariff, it takes about five minutes to check, and it is worth more than every price below.

Non-European visitors — American, Canadian, Australian, Japanese — were never covered by any of this, and the rest of the page is straightforwardly for you.

Six providers, and prices that actually diverge

The UK has six providers selling plans in our data, more than any other country covered here, and the competition shows up as genuine price dispersion rather than the cent-apart matching common elsewhere in Europe.

Every winner in that table is a price we read off the seller's own site — Airalo's and Saily's on 13 August 2026, Nomad's on 17 August 2026. Three of those five rows used to go to eSIM Go instead, and they no longer do. eSIM Go sells wholesale to resellers and publishes no consumer price at all: checked on esim-go.com on 18 August 2026, there is no basket, no checkout and no per-country page, only a Contact Sales button. Our rows for it — $8 at 3 GB, $14 at 10 GB, $22 at 20 GB — are figures no traveller can pay, and they can never be verified because there is nothing to read them against. See our eSIM Go page. The Holafly rows are indicative in the ordinary sense: a real shop whose prices we have not yet read. eSIMCard's rows have been withdrawn: we read its own pages on 18 August 2026, found the figures we held were wrong, and could not store the real ones. See our eSIMCard page.

One thing to know before you shop: Airalo sells the UK as two packages, Uki Mobile and Uki Mobile+, and both appear on its site with the same allowances at different prices. The 50 GB month is $39 as Uki Mobile and $54 as Uki Mobile+; the 10 GB month is $19 against $23.50. We quote Uki Mobile, the cheaper of the two, throughout this page. Airalo does not state what the plus package adds, so we cannot tell you whether the premium is worth paying — but the names are on the listings, so you can see which one you have landed on before you pay.

The winner at the two sizes most visitors buy is Nomad, on prices read at source: a verified $17.50 at 10 GB where Airalo's Uki Mobile wants $19 and Saily $18.99, and a verified $25 at 20 GB where Uki Mobile wants $31 and Saily $30.99. Earlier versions of this page gave both rows to eSIM Go and called it a good illustration of why brand recognition is a poor proxy for price. It was a better illustration of something else: the cheapest figure on the board belonged to the one supplier with no shop behind it.

Five to one for the same unlimited plan

Now the part that requires care. Our UK data contains three different products described as unlimited data for 30 days:

• Airalo Uki Mobile, $69.00 (verified)
• Holafly, $74.90 (verified)

That is a spread of more than five to one on a nominally identical product. Only the Airalo figure has been read from a provider's own checkout on a dated visit, which is exactly why we are showing you the discrepancy rather than picking the lowest and calling it the answer — the $14 is both the most attractive number here and the least substantiated.

The lesson is not that one of them is a bargain. It is that unlimited is not a specification. It is a marketing word covering products that differ in throttling thresholds, tethering rights, fair-use caps and what happens when you cross them — and those differences are where a $14 unlimited and a $74.90 unlimited actually diverge. If you are considering any unlimited plan for the UK, read the fair-use terms before the price, and check hotspot rights specifically if you are travelling with a laptop.

For most people the per-gigabyte plans settle it anyway. Nomad's ten-day unlimited at $33 costs more than its own verified 20 GB for a full month at $25.

EE, Three, and what changes once you leave London

EE has the widest 4G coverage in the UK at 99.8% of the population, the highest 5G availability at 77.4%, and the best overall Opensignal ratings, with average 4G speeds around 52.8 Mbps and 5G around 168.4 Mbps as of January 2026. O2 is strong at 99% 4G but described as uneven. Vodafone sits in similar territory.

In London, Manchester or Birmingham, this is close to irrelevant. Every network works, the 5G is dense, and the only connectivity problem you will actually meet is the Underground, where coverage depends on the line and the station rather than on your provider.

It changes on the way out. The UK's coverage gaps are rural and they are specific: the Highlands and the roads west of Fort William, mid-Wales, the North York Moors, parts of Cornwall and Devon, and the long stretches of the West Coast Main Line and the Scottish rail routes where trains run through cuttings and valleys. A trip that is London, Bath and York will not test any of this. A trip that is Edinburgh and then north will.

EE is the network to want for that, and its advantage is specifically geographic coverage for regional travel rather than raw speed. The catch is that we cannot tell you who rides it. No provider in our UK data names a host network. Holafly used to look like the exception, on a Three UK and Virgin Media O2 listing that came from our own records rather than from the seller; Airalo, Saily, Nomad and eSIMCard all leave the field blank too, and eSIM Go has no consumer page on which it could fill it in. So the practical instruction before a Scotland or Wales trip is to ask the provider directly which network you will be on, and to ignore the question entirely for a city break.

The high street SIM is a real competitor here

A UK prepaid SIM costs around $10 and requires no ID to activate. No registration, no passport, no counter with a queue — the UK is one of the easiest countries in Europe to walk into a shop and come out with working data.

At $10 that undercuts every eSIM in the table except the smallest, and Heathrow, Gatwick, Manchester and Edinburgh all sell them. It is a fair option, and unlike in most countries we are not going to tell you to walk past.

The reasons we would still buy an eSIM before flying are the ordinary ones and they are weaker here than usual: you land connected, there is no queue after a long-haul flight, and you keep your own number reachable on a second line. If your phone does not support eSIM — check the model list — the UK is a good place to fall back on plastic.

What we would do

Check your operator's UK roaming terms first. That single check decides whether anything below is relevant.

City break, three to five days: Saily's verified 3 GB at $8.99. London runs on transport apps and hotel wifi, and 3 GB covers it.

A week or two, cities and trains: Nomad's verified 10 GB at $17.50, the best checked price at the size most people need. Step up to its verified 20 GB at $25 if you are driving, tethering, or travelling with someone sharing your hotspot.

Scotland, Wales or the West Country: same sizes, but ask the provider which network you will be on before you buy, because none of them publish it. EE is the one to want — the 99.8% coverage figure is what matters once the motorway ends.

And treat every unlimited plan as a fair-use document to read rather than a price to compare.