What is data roaming, and should it be on or off?

Information verified on 26 October 2026 at the official sources listed below. This is not financial advice; check card settings, fees and limits with your bank before you pay. How we check information.

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The one rule: data roaming on for the travel eSIM line. For the UK line it is your choice, made with the arrival text in front of you. If your plan includes roaming where you are going, you may not need a travel eSIM. What each network charges is on the roaming hub; the switches are in data roaming settings.

What does data roaming mean?

The data roaming meaning: your phone uses mobile data on a network that is not your own, normally abroad. At home the switch does nothing. It is set on each line, not once for the whole phone.

Mobile data vs data roaming: they are two switches. Mobile data is the line’s connection to the internet. Data roaming decides whether that connection may use a foreign network. On an iPhone, each number has its own Data Roaming switch (Apple: turn Data Roaming on or off, checked on 24 October 2026).

Wi-Fi is outside all of this. WhatsApp, FaceTime and browsing over Wi-Fi use no mobile data and no roaming. Wi-Fi calling abroad is your network’s own service with its own rules, so check its page first. Aeroplane mode switches off every line at once, and you can turn Wi-Fi back on inside it.

Should data roaming be on or off?

Off on your UK line if you do not want its network’s charges. On for a travel eSIM line, because that eSIM connects to a network abroad.

Keep both lines on and Apple’s travel eSIM prompt, on iOS 26 and later, warns: “You might still incur roaming fees from your home eSIM” (Apple: use two eSIMs, checked on 24 October 2026). A common route to a bill is the wrong data line: the travel eSIM is in, but data still runs on the UK line.

Before you land, check which line carries data. With two lines active, you choose the one the phone uses for mobile data.

Will I be charged if data roaming is off?

Not for foreign data on that line, but possibly for a day of use. EE, Vodafone and Sky count a call you make or a text you send as using the phone abroad. Data roaming off does not switch that off.

Source: EE price guide · Vodafone Charges Guide · Sky Roaming Passport Plus.

Each network sets its own conditions. EE, Vodafone and Sky Mobile have the full rules; other networks are on the roaming hub.

The charge you can plan around is in the arrival text. Ofcom says that in another country your provider must send an automatic message, unless you opted out, “to explain any roaming charges or usage limits” (Ofcom: using your mobile abroad). Under General Condition C3.15, in force from 1 October 2024, the message is free. It shows whether the destination is in your plan, prices per minute, text and GB, and when any charge period starts and ends (Ofcom C3 guidance, PDF). Read it before you switch data roaming on.

A spend cap is the network’s own setting. The £45 cap is no longer the law: Ofcom says the statutory roaming protections ended in June 2022 (Ofcom: roaming customer protections). Sky sets a £45 data roaming spend cap a month per SIM by default (checked on 24 October 2026, Sky spend cap help). On EE and Vodafone you set your own.

Ships are the exception. Ofcom warns that at sea a phone “may instead connect to a ship’s satellite”, and charges “can be higher than normal roaming”. EE charges £16 per 10MB on ships. Data roaming off stops the data; aeroplane mode stops calls and texts too. The cruise page has the detail.

Does a travel eSIM need data roaming on?

Yes: a travel eSIM needs data roaming on, on its own line. It connects to a network in the country you visit, so its data goes through that line’s roaming setting. Follow the setting in your order e-mail.

Our plans are data only. Calls and texts stay on your UK line, so the table above still applies to it. The steps are in data roaming settings, and keeping your UK number covers calls.

If the travel eSIM shows no signal, check data roaming on that line first; no signal on an eSIM has the rest.

What is “current period roaming” on an iPhone?

It is a usage counter, not a switch. Apple’s UK page lists each app’s data use “from a current period” and the apps “that used data when you were roaming”. Reset Statistics clears both (Apple: use mobile data, checked on 24 October 2026). The period runs from the last reset, so it need not match your bill.

The figure is an estimate. Apple: “To get the most accurate mobile data usage from a current period, contact your network provider.” Go by your network’s bill, not the phone’s count. For our plans, see check your data usage.

Frequently asked questions

Sources are linked in the text; reviewed by Nadezhda Semenova. For individualised advice on your contract, ask your network.

Unfamiliar term? See the eSIM glossary.