Product info
Northern Ireland eSIM plans
| Unlimited data · 5 days | $15.99 | Buy eSIM |
| Ohayu recommendsUnlimited data · 10 days | $27.99 | Buy eSIM |
| Unlimited data · 15 days | $37.99 | Buy eSIM |
| Unlimited data · 30 days | $48.99 | Buy eSIM |
| 3GB prepaid eSIM · 14 days | $8.49$2.83 / GB | Buy eSIM |
| 5GB prepaid eSIM · 30 days | $11.99$2.40 / GB | Buy eSIM |
| 10GB prepaid eSIM · 30 days | $18.49$1.85 / GB | Buy eSIM |
| 15GB prepaid eSIM · 60 days | $23.99$1.60 / GB | Buy eSIM |
| 20GB prepaid eSIM · 90 days | $29.49$1.47 / GB | Buy eSIM |
| 50GB prepaid eSIM · 90 days | $74.99$1.50 / GB | Buy eSIM |
You can install your eSIM before the trip and activate it when you arrive in United Kingdom. Validity starts after eSIM activation.
Plan details
How much mobile data you need
What's the best eSIM for Northern Ireland?
A few days – 3 GB
Maps, Belfast, the Causeway.
A week – 10 GB
The coast, the Mournes, Derry.
Ireland as a whole – 20 GB
Add an Ireland plan for the Republic.
A longer stay – Unlimited
Tethering from Belfast.
Coverage and network
Coverage and the border you cannot see
United Kingdom mobile networks
Northern Ireland is part of the United Kingdom, so a UK plan applies. The complication is geographic: it shares a 500 km land border with the Republic, there are no checkpoints, and the networks on either side overlap freely.
Speedtest Global Index · Mobile · United Kingdom · June 2026
Download
75.57 Mbps
Upload
8.95 Mbps
Latency
31 ms
Global rank
#59 of 98
Northern Ireland, specifically
- Belfast: Well covered across the city, the Titanic Quarter and the university area.
- The border: This is the thing to understand. The border is unmarked - you cross it on ordinary roads with no sign that you have - and Irish networks reach well into the north while UK networks reach south. Your phone can switch to an Irish network without you leaving Northern Ireland, which takes you outside a UK plan.
- The Causeway Coast: The Giant's Causeway, Carrick-a-Rede and the coast road are covered. The cliff paths dip in places.
- The Mournes and the Sperrins: The mountain areas have real gaps, and the Mourne Wall walk should be treated as offline.
- Derry and the northwest: Covered in the city, but it sits directly on the border and network switching there is especially common.
The UK, not the Republic
This plan covers all of the United Kingdom including Northern Ireland. The Republic of Ireland is a separate destination - and since Brexit, outside UK roaming arrangements.
How to install eSIM
Connected in 3 steps
- 01
Buy before you fly
Choose your data plan before your trip.
- 02
Download & install
Log in to your account, tap your eSIM, and follow the on-screen instructions.
- 03
Land & activate
Activate when you arrive in United Kingdom. Turn on roaming for the eSIM and it connects to a local network.
Before you buy, make sure your phone supports eSIM — see Ohayu compatible devices list or dial *#06#. It's a free request to your phone's settings. If you see the EID number — your phone is eSIM-compatible.
Arriving in Northern Ireland
Belfast's two airports
Belfast has two airports - International, 30 km northwest, and City, next to the docks - both with free terminal Wi-Fi. Many visitors arrive by ferry from Scotland or by road from Dublin instead.
Side by side
Northern Ireland eSIM Comparison
Indicative comparison based on publicly listed the UK plans as of August 2026. Competitor pricing and policies change - check their sites for current terms.
Frequently asked questions
Does a UK plan work in the Republic of Ireland?
No, and this is the single most useful thing on this page. Since Brexit the UK is outside EU roaming, so a UK plan does not cover the Republic - and because the border is completely unmarked, people cross it without realising. Dublin is two hours from Belfast and a lot of trips do both.
Worse, you do not have to cross at all: Irish masts reach into Northern Ireland, particularly around Derry, Newry and Fermanagh, and a phone will sometimes prefer one. Check the network name if something looks wrong, and pin your operator manually if it keeps happening.
Where to buy a SIM card in Belfast?
EE, Vodafone and O2 have shops in Victoria Square and on Donegall Place, and the supermarkets sell prepaid. The UK does not register pay-as-you-go SIMs, so it is a quick purchase - price is the reason to sort data out beforehand rather than paperwork.
Is there coverage on the Causeway Coast?
Along the road and at the main sites, yes. The Causeway itself, Carrick-a-Rede and Dunluce are all covered. The cliff-top paths between them have patchy stretches, and the weather there changes fast enough that offline maps are sensible.
eSIM not working in Northern Ireland?
First check which network you are on - near the border a phone often registers on an Irish one, which a UK plan does not cover. If you are on a UK network, set Ohayu as the data line, allow roaming, then toggle Airplane mode. Chat and support@ohayu.com are open 24/7.
