How can I check O2's international calling rate for a specific country?

Use O2's official international calling tool on their website. Enter the country you want to call, and it will show the most up-to-date standard per-minute rate. You can also check rates through the My O2 app.

What is the O2 Travel Bolt On?

The O2 Travel Bolt On is a daily add-on that gives you a bundle of minutes, texts, and data when roaming outside Europe in destinations like the USA, Canada, and Australia. You're only charged on days you actually use your phone.

Why can't I make international calls on O2?

O2 sometimes places an international call bar on accounts by default. Check your My O2 account or app to disable any active call bars. Also ensure you're using the correct dialling format: start with + followed by the country code and local number, dropping any leading zero.

Your Complete Guide to O2 International Calls

Q: Can I use my O2 plan minutes to call international numbers from the UK?

No. Your standard O2 minutes are strictly for calling UK numbers from within the UK. They won't cover calls you make to international destinations. You'll need an International Bolt On or pay O2's standard per-minute rates.

Calling a colleague in another country on your O2 mobile can be perfectly simple and affordable. It can also be a one-way ticket to a shocking phone bill. The difference all comes down to one key detail: are you physically in the UK calling abroad, or are you travelling and using your phone in another country?

Getting this right is the first step to keeping your costs in check. This guide is a UK-focused overview of O2 international calls.

Breaking Down Your O2 International Calling Options

The international calling market is valued in the billions. If you're an O2 customer, how you avoid overspending depends on your situation.

Whether you're dialling a client in New York from your London office or checking emails on a beach in Spain, O2 has a specific set of rules and charges that apply.

Where You Are Matters Most

Your physical location when you use your phone is the deciding factor. O2's international services split into two categories, each with its own pricing:

Calling abroad from the UK: Dialling an international number while you are physically in the United Kingdom.
Using your O2 phone abroad (Roaming): Making calls, sending texts, or using data while you are travelling outside the UK.

Here's a quick summary of the main ways you'll be charged.

O2 International Calling at a Glance

Calling Scenario	What It Covers	Best For
Roaming in O2's Europe Zone	Using your normal UK plan's minutes, texts, and data in 40+ European countries.	Short trips and business travel within Europe without worrying about extra fees.
O2 Travel Bolt On	A fixed daily charge for a set bundle of minutes, texts, and data when roaming outside of Europe.	Travellers visiting countries like the USA, Canada, or Australia who need to stay connected.
Standard Per-Minute Rates	Pay-as-you-go, per-minute charges for calls made from the UK to international numbers.	Occasional, short calls from the UK when you don't have a specific add-on.

What's cost-effective for a holiday in France is completely different from what you'd want for regularly calling suppliers in India from your UK base.

Where you are and where you're calling determines what you'll pay. If you're weighing your options across providers, our guide on Three UK international calls is a useful comparison.

How to Call Abroad From The UK on O2

This is the classic "international call" scenario: you are in the UK, using your O2 mobile to phone someone in another country. Without a special add-on, this can be expensive, as calls are charged on a per-minute basis.

Dialling friends, family, or business contacts in places like India, Pakistan, the USA, or Australia can rack up some serious charges on a standard O2 plan.

A smartphone with a world map, EU flag, travel icon, and Euro coins illustrating international roaming options.

O2's Standard Per-Minute Rates

If you make an occasional international call, you'll be charged O2's standard pay-as-you-go rates. These vary significantly by destination. Here are some examples of typical per-minute rates for calling a mobile number from the UK:

USA: £1.50 per minute
India: £1.50 per minute
Pakistan: £1.50 per minute
Australia: £1.50 per minute

These rates can change, so always check O2's international calling online tool for the exact price before you dial.

O2's International Bolt On

For more regular callers, O2 offers its International Bolt On. This is a monthly add-on that gives you a bundle of discounted minutes for a flat fee, which can slash those high per-minute rates.

The International Bolt On turns unpredictable pay-as-you-go fees into a fixed monthly cost. If you regularly call family or clients overseas, that predictability alone can be worth it.

The Bolt On makes the most sense if you call abroad consistently. If you only do it once in a blue moon, standard rates or other options might work out cheaper.

Checking Rates and Activating the Bolt On

Here's how to set it up:

Open the My O2 App: Just log into your account on your phone.
Head to 'Bolt Ons': Look for the section where you can manage add-ons.
Find 'International': This is where you'll see the details for the International Bolt On.
Check Specific Rates: To be absolutely sure, use O2's international calling online tool to look up the exact per-minute charge for any country.
Activate if It Works for You: If the Bolt On covers the right countries and the price is right, you can add it to your account instantly.

A quick check before you commit saves you from paying more than you need to.

Using Your O2 Phone When You're Abroad (Roaming)

It’s a classic mix-up: international calling versus roaming. They sound similar, but they're completely different. Roaming is when you use your UK phone in another country. The costs for this depend entirely on where you are travelling.

Getting this wrong is how people end up with sky-high bills when they get back home.

Roaming in The O2 Europe Zone

For most trips to Europe, O2 keeps things simple. Their "Europe Zone" lets you use your phone just like you do at home. This means your normal allowance of minutes, texts, and data works across more than 40 European destinations without any extra charges. This is part of your O2 Travel inclusive zones.

So, whether you're in Spain, France, Italy, or Ireland, your plan comes with you. Just be mindful of O2’s fair usage policy, which is in place to prevent people from using their UK SIM abroad permanently. It caps your data roaming at 25GB a month, even if your plan back home gives you more.

Roaming Outside Europe with the O2 Travel Bolt On

Once you step outside the O2 Europe Zone, standard roaming charges can be eye-watering. That's why O2 created the O2 Travel Bolt On.

For a fixed daily price, the Bolt On gives you a bundle of minutes, texts, and data in long-haul destinations like the USA, Canada, and Australia. It only charges you on days you actually use your phone. Without it, you're looking at steep per-minute and per-megabyte rates that add up fast.

Also worth thinking about: managing incoming calls while abroad. Forwarding calls to voicemail or another number can help you dodge roaming charges just for answering.

Wi-Fi Calling is another option. It routes calls over a Wi-Fi network instead of the cellular one, which can sidestep roaming fees entirely. Our guide on what is Wi-Fi calling explains how it works.

Before you travel, double-check the O2 website for rates at your destination.

A Smarter Way to Make Frequent International Calls

If you regularly make O2 international calls from the UK, mobile network add-ons aren't always the cheapest option. There's an alternative worth knowing about: Voice over Internet Protocol, or VoIP.

VoIP makes calls using your Wi-Fi or mobile data instead of the traditional phone network. The rates tend to be significantly lower, and you get more control over what you spend.

Person in an airport holding a smartphone displaying 'O2 Travel Bolt On' app, with a plane outside.

With a good VoIP service, you can see the exact per-minute rate for any country before you dial. You know exactly what the call will cost.

Why VoIP is a Great Alternative

VoIP services like CallSky are designed specifically for affordable international calls. Their biggest advantage over mobile networks is price.

The reason is that VoIP providers don't have to deal with the web of traditional network fees that inflate mobile rates. Think about things like Mobile Termination Rates (MTRs). These are the regulated fees that mobile companies charge each other just to connect a call from one network to another. These behind-the-scenes costs are a big reason why standard international call prices stay high.

By routing calls over the internet, services like CallSky offer a pay-as-you-go model with no contracts and no monthly subscriptions. You top up your credit, and it never expires.

That works well for small businesses keeping in touch with overseas clients and for families spread across different countries. You only pay for the minutes you actually use.

We have a more detailed guide on using VoIP for international calls if you want the full breakdown. Whether you're calling a supplier in India or family in Australia, moving away from monthly add-ons usually means lower costs.

Troubleshooting Common O2 International Call Problems

It’s happened to all of us. You’ve got everything lined up, you go to make that important international call, and... nothing. It just won't connect. When your O2 international calls fail, it’s usually down to one of a few simple issues, and thankfully, they’re often quick to fix.

Let’s walk through the most common culprits so you can get your call connected.

Person typing on a laptop with a VoIP call screen showing 'VoIP - low rates', next to headphones and coffee.

More often than not, the problem is a setting on your account. To prevent unexpected bills, O2 sometimes puts an international call bar on accounts by default. It's a safety net, but it can get in the way when you actually need to call abroad.

Is a Call Bar Blocking You?

The first place to look is your My O2 account, either on the website or through the app. You can typically find and disable any active call bars there. If you're having trouble locating the setting, a quick chat with O2's customer service team will get it sorted.

Another common issue is getting the dialling format wrong. It's a simple mistake that stops calls from connecting, but it's easy to fix.

The golden rule for any international number is to start with the plus symbol (+). Right after that, add the country code and then the local number. For instance, a call to the United States should look like +1 followed by the area code and number. Just remember to drop the leading zero from the local number if it has one.

Using this universal format tells the network exactly where to send your call, no matter where you are.

What to Do About Unexpected Charges

That sinking feeling when you see a charge on your bill you weren't expecting is all too familiar. Your best bet for getting to the bottom of it is the My O2 app. Log in and pull up your itemised usage for that billing period.

Here’s what to look for:

Check the call type: Was the call made from the UK to another country, or was it a roaming charge from when you were travelling? The app will specify this.
Review your Bolt Ons: Double-check that your O2 Travel or International Bolt On was active at the time. Also, confirm if the country you called was actually covered by the Bolt On's allowance.

Once you know where the charge came from, you can contact O2 to dispute it or at least understand what happened.

Common Questions About O2 International Calls

Here are the questions that come up most often about O2 international calls.

A big one we hear all the time is, "Can I use my inclusive plan minutes to call another country from the UK?" The simple answer is no. Your standard O2 minutes are strictly for calling UK numbers from within the UK. They won't cover calls you make to international destinations.

So, how do you figure out what a specific call will actually cost you?

How Can I Check O2's Rate for a Country?

Use O2's official international calling tool on their website. Enter the country you want to call, and it shows the current standard rate. Worth doing before any international call so you're not caught off guard.

That raises a fair question: when does it make sense to look beyond O2?

If you find yourself making international calls on a regular basis, a VoIP service like CallSky is almost always the cheaper option. O2's add-ons are great for occasional use or for when you're travelling, but for frequent calls from the UK, VoIP's lower per-minute rates offer much better long-term value.

If you're calling family in Pakistan or a client in the USA a few times every month, those standard O2 rates (or even the cost of a Bolt On) will add up. A pay-as-you-go VoIP service is built for exactly this kind of regular use and typically costs a fraction of the price.

CallSky lets you call 180+ countries with pay-as-you-go credit that never expires. No subscription needed.