How-to · OpenDial Blog
How to Call the UK from the US Without Roaming Charges
April 1, 2026 · 6 min read
Calling the United Kingdom from the US doesn't have to mean expensive roaming or confusing workarounds. Here's the clearest way to reach any UK landline or mobile from your browser, for a few cents a minute.
Why calling the UK from the US still trips people up
The UK and the US share a lot — language, business ties, family connections — but phone networks don't. US carriers treat calls to UK numbers as international calls, which means per-minute rates that can range from $0.25 to over $1 depending on your plan. For anyone making calls frequently, that adds up quickly.
Apps like WhatsApp and FaceTime work well when the other person is also on the same app and has reliable internet. But when you need to reach a UK landline, a small business, a GP surgery, a bank, or someone who simply doesn't use those apps, you need a service that can dial a real UK phone number directly.
The UK phone number format explained
UK phone numbers use country code +44. When dialing from the US, drop the leading 0 from the local UK number and add +44 in front. So a London number written locally as 020 7946 0000 becomes +44 20 7946 0000 when dialed internationally.
UK mobile numbers start with 07 locally, which becomes +44 7 when dialed from abroad. UK geographic numbers typically start with 01 or 02 locally. Numbers starting with 08 are non-geographic — some are free, some are premium-rate — and calling them from abroad can be more expensive depending on the service you use.
What browser-based calling looks like in practice
Browser-based VoIP calling lets you dial any UK number directly from your laptop or phone, without installing an app or changing your phone plan. You open the dialer in your browser, type the number in international format, and call. The call goes over your internet connection, not your mobile network.
OpenDial supports calls to UK landlines and mobiles. Rates to the UK are typically around 1–3 cents per minute, and there's no monthly subscription or credit minimum. You pay only for the minutes you use, which makes it practical for occasional calls rather than just heavy users.
UK landlines vs. mobiles — does it matter?
Yes, slightly. Calling a UK landline (numbers starting with 01, 02, or 03) is usually cheaper per minute than calling a UK mobile (numbers starting with 07). This is a standard difference in international calling rates, not specific to any one service.
For most everyday use — calling a family member, a business, or a hotel — the difference is small enough not to matter. But if you're making long calls regularly to UK mobiles, it's worth checking per-minute rates to the mobile range before you start.
When your regular carrier is actually the right answer
Some US carriers now include international calling in certain plans. T-Mobile's Magenta plan includes calling to the UK at no extra charge; other carriers offer international day passes. If you're already on one of these plans and make UK calls often, your carrier may be the cheapest option.
The situations where browser-based VoIP tends to win are: you're traveling abroad and want to avoid roaming on your US number, you're on a basic carrier plan without international perks, you need to call UK numbers only occasionally and don't want to pay a monthly add-on, or you're on Wi-Fi and want to preserve your phone's cellular data.
Making the call from abroad — what changes
If you're the one traveling — visiting the UK or a third country — and you need to call a UK number, the same browser-based approach applies. You connect to local Wi-Fi or a reliable internet connection, open OpenDial in your browser, and dial the UK number with the +44 prefix. Your roaming plan never comes into it.
One thing to keep in mind: if you're calling a UK business with a local callback number or an 0800 freephone number, check whether that number is dialable from abroad. Many UK freephone numbers cannot be reached from outside the UK even with VoIP. Geographic numbers (01, 02) and mobile numbers (07) work reliably from anywhere.