Crossing the Irish border: everything you need to know!

Ireland is a country divided in two: in the south and west, the nation of Ireland (which I will refer to as the Republic of Ireland to avoid confusion), and in the northeast the province of Northern Ireland which is part of the United Kingdom. Both have plenty to do and see, and it would be a crime to make a trip to Ireland and not cross the border. But what does that entail? Here is your guide to crossing the Irish border.

crossing the Irish border
Glenveagh National Park, Co Donegal, Republic of Ireland

Do I need a passport?

There are no border formalities between the Republic of Ireland and the United Kingdom. This means that you can cross freely from one to the other without the need for documentation; however, you should consider what happens if you encounter problems across the border and need to prove your right to be in the country. It is therefore important to always carry a passport or national identity card with you if you are crossing from one country to the other.

If you need a visa to visit the Republic of Ireland or the United Kingdom, you need to make sure this has been secured and is in your passport prior to crossing into the new country. Again, if you don’t have a valid visa you are unlikely to be stopped, but this is not legal and it only takes an incident or accident outside your control for you to find yourself in trouble. Don’t put yourself in that position.

crossing the Irish border
Lough Erne, Co Fermanagh, Northern Ireland

Can I take my rental car across the border?

In short, yes – but you will need to pay for additional insurance and breakdown cover in the other country. This is generally not expensive, but shop around and check before you book. It is very important that you do declare that you will take the car outside the country you rented it in, otherwise you will be faced with a huge bill in the event of a problem. Note that you can pick up a car in one country and return it in the other, but you will be charged a very high fee to do so, so it is always best to return the car in the country you hired it in.

crossing the Irish border
Donegal Town, Co Donegal, Republic of Ireland

Do the Republic of Ireland and Northern Ireland use the same currency?

No, they don’t. Northern Ireland is part of the UK and uses the British Pound, and the Republic of Ireland uses the Euro. The two currencies are generally not accepted on the other side of the border, so you will need to change money or use an ATM as soon as possible to get cash in the right currency.

crossing the Irish border
Hillsborough, Co Down, Northern Ireland

Do both countries drive on the same side of the road? What about traffic signage?

Both countries drive on the left, and vehicles have the steering wheel on the right. However, the Republic of Ireland measures speed and distance using the metric system (kilometres), while Northern Ireland uses miles. Make sure you don’t forget this when crossing the border, as speed limits will immediately change to the new system with little or no warning. All rental cars will display both units of measurement.

Traffic signs are slightly different on either side of the border, but other than miles/kilometres, in all other respects, the differences are easy to understand.

crossing the Irish border
Heading into one of the Ghaeltacht regions, Co Donegal, Republic of Ireland

Is the language the same? I have heard that there is an Irish language?

The predominant language in the whole of Ireland is English. The Republic of Ireland also has Irish, a Gaelic language similar to Welsh or Scots, as an official language, and you will see it on signage. Irish is also gaining in popularity in Northern Ireland, although you will not usually see it written north of the border.

There are small areas of the Republic of Ireland designated as Ghaeltacht, or fully Irish-speaking areas. In these regions you may find the only signage is in Irish, and English is not commonly spoken. However, everyone is able speak English so just ask if you need help!

crossing the Irish border
Ballintoy, Co Antrim, Northern Ireland

Do the two countries share a cellphone network?

No, the two countries maintain separate networks. However, in most cases, if you have a contract with a UK or ROI network you will be able to use your phone in the other country at no extra cost – confirm with your provider before travelling. For anyone else, roaming rates will generally be the same for both countries, but again, check before travelling.

Phones will automatically switch networks close to the border. Note that your phone may transfer to the other country’s network before you actually cross the line!

crossing the Irish border
Slieve League cliffs, Co Donegal, Republic of Ireland

What will it be like cross the Irish border?

Underwhelming! Driving from the Republic to Northern Ireland is no different to driving from one Irish county or US state to another. If you are lucky, there may be a sign saying “Welcome to Ireland”, or simply “Northern Ireland” as you head north. On other roads, the only indication will be a sign giving the speed in kilometres/miles, and it is easy to cross without noticing!

crossing the Irish border
Dunluce Castle, Co Antrim, Northern Ireland

So why should I visit both sides of the border?

The differences between the Republic of Ireland and Northern Ireland can be fascinating, but so can the similarities. Both parts of Ireland share stunning landscapes and friendly people, and there are some great experiences to be had wherever you go. So arm yourself with the information in this post, and go out and explore the whole of this great island!

Inspired to discover a little more about Northern Ireland? Check out my other posts!
Northern Ireland: Discover the highlights of Derry/Londonderry
5 Reasons you will love Northern Ireland…
Discover Northern Ireland’s beautiful Causeway Coast
Portrush to Castlerock: Discover Northern Ireland’s northwest coast
The Mourne Mountains: Northern Ireland’s beautiful southeast

Never miss a post from Reading the Book – sign up to be the first to hear about new posts!

View previous campaigns.

Did you find “Crossing the Irish border” useful? Pin it!

crossing the Irish border

Hi! I’m Jill, and I’m a British travel blogger who has been travelling for more than 15 years, visiting over 60 countries on 6 continents. I love to travel both solo and with groups, and to discover the cultures and peoples of the countries I visit. And I love to share a good story or two along the way!


  1. What a cool descriptive pool of useful information! Pinned it, as it will definitely be handy if I want to cross over to Ireland by land.

  2. I love the way you answer your own questions. My biggest query would revolve around mobile network. I’m so glad that you included that in the list. Despite all the anxiety I’m sure that the trip must have definitely been worth your while. 🙂

  3. Really interesting post – thanks for sharing. Of course, I am really wondering what will happen when (if) Brexit happens. I am British and have never been to North or Southern Ireland…and I think I better get my skates on whilst it’s still possible to seamlessly pass between the two on a British passport!

  4. I genuinely never knew there were so many differences between northern and Southern Ireland, and I live in the UK! Thanks for sharing your know-how!

  5. Great breakdown of the questions. I recently did a road trip in Ireland and we debated going to Belfast, but we weren’t really sure if we could in our rental car. I guess I will have to go back now that I know a lot more details, they are so different. Thanks for sharing!

    1. Thanks Valerie! There really aren’t a lot of resources out there about these borders which are easy to cross, but are still between two different countries with different laws and infrastructures. I needed this information when I went but it just didn’t exist. You should definitely write the Estonia/Latvia equivalent!

  6. Southern Ireland is known as Eire so my mum told me who comes from there and stretches right up to the North west of the actual island.

Leave a Reply

Your email address will not be published. Required fields are marked *