Sure Guernsey: an eSIM sent by email, and rewards for topping up
Sure Guernsey's pay-as-you-go page offers an eSIM and a physical SIM. Its eSIM request page says you enter an email address while on Wi-Fi or 4G or 5G, after which an activation QR code arrives within minutes. At the time of checking, topping up through the MySure website or app earned unlimited data with local minutes and texts: £5 gave 500 for 7 days, £10 gave 1,000 for 14 days and £20 or more gave 10,000 for 30 days.
Topping up in a shop or with Payzone earns data rewards instead, listed as 5 GB, 10 GB or 20 GB, and the eSIM page lists Instant Top Up rewards of 10 GB for £10 (14 days) and 20 GB for £20 or more (30 days). A footnote says new pay-as-you-go plans are capped at 10 Mbps, dropping to 7 Mbps after 1 GB in a day. A balance check is *#100#. Credit added on or after 10 June 2026 expires after six months. The pages do not say whether a visitor needs to show identification.
What a megabyte costs when you are not on a plan
Sure Guernsey's out-of-plan charges page lists local internet usage at 15p per megabyte, in 1 MB steps, and texts at 25p each to all destinations. JT's Guernsey pay-as-you-go page lists data outside a bundle at 21p per megabyte, a text at 21p and calls between Channel Islands numbers at 54p a minute plus a 20p connection fee. So a 20 MB app update with no active plan would cost about £3 on Sure or £4.20 on JT, going by those published rates.
That is why the order matters: buy the reward or bundle first, then let the phone use mobile data. If you are on a pay-as-you-go account, switch off automatic updates and cloud backup until a plan is active.
JT's bundles and its starter pack
JT's Guernsey page describes Big Bundles bought by exchanging credit, each valid 30 days with unlimited local minutes and texts: 5 GB costs £10, 20 GB costs £15 and unlimited data costs £20. It says a new physical pay-as-you-go pack from a JT shop comes with 5 GB of local data and 50 texts and 50 minutes for Channel Islands mobiles, and that a top-up of £5 or more keeps credit valid for seven months.
JT also lists roaming data bundles for the UK and Europe for use when travelling out of the islands: 2 GB for £6, 5 GB for £9 and 10 GB for £16. For a visitor, the starter pack is the interesting detail, because it gives some data before any top-up. The page does not say what ID is needed to buy one.
The regulator: mast audits, not coverage maps
The GCRA says operators in Guernsey must keep emissions from their radio masts within the ICNIRP standards, and that its audits measure emissions and review the operators' safety processes. It reports that the last comprehensive audit of masts across the Channel Islands, in 2017, examined all 274 sites and found them well within the ICNIRP limits, and that the most recent audit was completed in September 2024, focusing on new and upgraded masts and a sample of existing ones, with additional audits covering masts in Alderney and Sark.
Its interactive maps cover Guernsey (including Herm), Jersey, Sark and Alderney and let you locate individual mast sites and open the audit reports for each. They are mast audit maps, not signal-strength maps. We found no official coverage statement for Sark or Herm, so if your plans include either, ask your accommodation what works there before you rely on mobile data.
Photo ID, passports and the electronic travel authorisation
Visit Guernsey's page says that arriving direct from the UK or the Republic of Ireland means no passport is needed, but all visitors need some form of photographic identification. Anyone arriving from outside those two, whatever their nationality, must hold a valid passport. It adds that French nationals may make a day trip on a direct ferry with a national identity card until the end of the 2026 season.
It also says that on and after 23 April 2026 an electronic travel authorisation becomes a requirement for non-visa nationals travelling from outside the Common Travel Area directly to the islands, and refers to a States of Guernsey press release. If in doubt about acceptable ID, it says to contact your carrier.
Island hopping: Alderney, Sark, Herm and Jersey
The tourist board lists year-round daily flights to Alderney and Jersey, a daily ferry between Guernsey and Alderney from March to October, a year-round ferry to Sark with multiple sailings each day, year-round boat travel to Herm from St Peter Port Harbour and a passenger ferry between Guernsey and Jersey from March to October, five days a week. Timetables change, so check each operator before you book, and keep tickets and your accommodation details on the phone in case of a signal gap.
A day trip is a good reason to carry offline maps. Because we found no official statement of coverage on the smaller islands, treat any signal there as a bonus.
Emergency numbers
The Guernsey Police home page gives 999 for emergencies and 01481 222222 for non-emergency contact, and describes the service as 24-7. Our Guernsey plan page covers data before you travel.
Networks our Guernsey plans use
These are the operators named on our plans for Guernsey, taken from the plan data, so the list follows the catalogue.
- JT5G
- JT (Jersey) Ltd5G
- Sure5G