Last updated: 20 October 2026
The simplest USA SIM card for a tourist is not a card at all: it is a US eSIM you buy and install before you fly. It connects as soon as you land, needs no store visit, and leaves your home SIM in the phone for calls and texts. A prepaid SIM from a US phone store also works, if your phone is unlocked and you have time to find a shop. Roaming on your home network is the easiest of all, but on many UK, European and Australian plans the USA is outside the included zone and costs far more.
With us, a week of US data costs US$11.99 (about £8.99, €10.68 or A$17.16) with 1.5 GB a day.
Pound, euro and Australian dollar amounts use the European Central Bank rate of 19 October 2026 (US$1 = £0.7502 = €0.8909 = A$1.4314). Your card may convert at a slightly different rate, and some cards add a foreign transaction fee.
Your three options
| A US eSIM bought before you fly | A prepaid SIM in the US | Roaming on your home network | |
|---|---|---|---|
| Where you get it | Online, installed at home on Wi-Fi | A carrier store or large retailer in the US | Nothing to buy: your plan, a pass or an add-on |
| When it works | As soon as you land | After you find a shop and activate it | As soon as you land |
| Your home number | Stays on in the same phone for calls and texts | Usually removed from the phone, unless your phone takes two lines | Stays on |
| Phone needs | eSIM support and an unlocked phone | An unlocked phone | Nothing |
| US phone number | No: data only | Yes | No |
| Typical cost for a week | US$11.99 with us | Varies by carrier and plan | From nothing to a daily fee; see below |
Pick the eSIM if you mainly need data for maps, ride-hailing, messaging and your bank's app. Pick a prepaid SIM if you need a US phone number, for example to receive calls from US businesses during a long stay. Stay on roaming if your plan already includes the USA at no or little extra cost.
Our US plans
From our catalogue, checked on 20 October 2026:
| Plan | US dollars | Pounds | Euros | Australian dollars |
|---|---|---|---|---|
| 1 day, 0.6 GB | $2.99 | £2.24 | €2.66 | A$4.28 |
| 3 days, 1.5 GB a day | $7.99 | £5.99 | €7.12 | A$11.44 |
| 5 days, 1.5 GB a day | $9.99 | £7.49 | €8.90 | A$14.30 |
| 7 days, 1.5 GB a day | $11.99 | £8.99 | €10.68 | A$17.16 |
| 15 days, 1.5 GB a day | $17.99 | £13.50 | €16.03 | A$25.75 |
| 30 days, 1.5 GB a day | $23.99 | £18.00 | €21.37 | A$34.34 |
| 7 days, unlimited | $17.99 | £13.50 | €16.03 | A$25.75 |
| 15 days, unlimited | $27.99 | £21.00 | €24.94 | A$40.06 |
The days start when the eSIM first connects in the US, not when you install it, so you can set it up at home before you go. See all plans on our USA page.
From the UK: what your network charges in the USA
The USA is outside the UK networks' European roaming, so most plans charge extra there. From our network guides, checked in October 2026:
| Network | Using your phone in the USA |
|---|---|
| Sky Mobile | £2 per 24 hours with Roaming Passport Plus, on days you use it: a week is £14 |
| giffgaff | Not on your plan: 20p per MB from credit (1 GB is over £200), £1 a minute to make or receive calls, or a USA travel data add-on bought in the app |
| SMARTY | Out of plan add-ons at 10p per MB in the USA, within a £45 limit |
| Tesco Mobile | 1p per MB of data |
| Lebara | An 8 or 15-day add-on, £5 for 4 GB in the USA |
| iD Mobile | A Roam Beyond add-on, from £5 |
| VOXI | A Global Roaming Pass, from £16 for 2 GB |
On the larger networks it depends on your plan:
- Three lists the USA in its Go Roam Around the World zone. On plans without roaming built in, Three's own roaming page puts the daily roaming charge at £7 a day, or £8 a day if you joined or upgraded on or after 18 December 2025 (from 1 April 2026): a week is £49 to £56. Some older Three plans have roaming built in, so check yours.
- Vodafone's roaming page lists the USA among the destinations included on its Xtra Global Roam plans; on its other plans you need a roaming Extra or a daily charge.
- O2 includes some destinations outside Europe on its Volt, Plus and Ultimate plans, and sells a Travel Bolt On at £7 a day in selected destinations.
- EE shows its USA prices only in its destination checker and account: look up the USA there before you fly.
The short version for UK visitors: on Sky, Tesco Mobile or a plan that includes the USA, roaming is cheap or free and you may need nothing else. On Three's or O2's daily charges, giffgaff, SMARTY or any plan where the USA costs a daily fee or a pass, a US eSIM at £8.99 a week usually costs less.
From Europe
EU plans include roaming in the EU, not in the USA. Most European networks charge for the USA by the day, by the megabyte, or with a pass bought in their app. Check what yours charges for "zone 2", "rest of the world" or "USA" before you fly. If it is more than about €1.50 a day, our week of US data at €10.68 is likely to cost less.
From Australia
Australian networks sell roaming as daily fees or packs. For the USA, Telstra charges $10 a day with 2 GB on its International Day Pass (Zone 2), Optus $5 a day for 5 GB on Choice Plus, Plus Family and Plus Promo plans or $10 for each 1 GB pass on other postpaid plans, and Vodafone $5 a day with $5 Roaming on postpaid plans, as listed on their roaming pages on 20 October 2026. More in our guides to Telstra, Optus, Vodafone, ALDI Mobile, amaysim, Belong and Boost Mobile. For a two-week trip, compare your network's daily fee or pack with our 15-day US plan at A$25.75.
From Canada
Canadian plans often include the USA, or charge a daily fee or a pass for it. Our guide will my Canadian phone work in the USA? compares Rogers, Bell, Telus, Koodo, Fido and Freedom with a US eSIM.
From India
Visiting family or studying in the US on an Indian number? Airtel and Jio international roaming in the USA compares their USA packs with a US eSIM, in rupees, and covers keeping your Indian number on for OTPs.
Keeping your home number on
With an eSIM, your home SIM stays in the phone. That matters for bank codes and messages from home.
- Check your phone takes an eSIM and is unlocked: does my phone support eSIM? and is my phone unlocked?
- Install the US eSIM at home on Wi-Fi: iPhone or Android.
- When you land, set the eSIM as your data line and turn data roaming on for it only.
- Turn data roaming off on your home line, so it cannot start a daily fee or use pay-as-you-go data. Receiving texts is free on many plans abroad, so bank codes usually still arrive; check your own network's terms.
- Make calls over WhatsApp or FaceTime on the eSIM's data. Calls on your home line are charged at your network's US roaming rates.
If the eSIM shows No Service when you land, see eSIM not working abroad.
Buying a prepaid SIM in the US
The large US carriers and their prepaid brands sell prepaid SIM cards and eSIMs in their own stores and in large retailers. You need an unlocked phone that works on US networks, and some plans ask you to set up an account or download an app. It makes sense for a long stay, or when you need a US number. For a one or two-week holiday, buying online before you fly saves the trip to a store on your first day.
FAQ
Can I use my UK phone in the USA?
Yes. Any recent UK phone works on US networks. What changes is the cost: the USA is outside UK networks' European roaming, so many plans charge a daily fee, an add-on or pay-as-you-go rates there. Sky Mobile, for example, charges £2 a day, Three £7 or £8 a day on plans without roaming built in, and giffgaff 20p per MB without an add-on.
What is the best SIM card for the USA?
For most visitors, a US eSIM bought before you fly: it works when you land and keeps your home number on in the same phone. With us, 7 days with 1.5 GB a day costs US$11.99 (about £8.99). A prepaid SIM from a US store is better if you need a US phone number.
Do I need a US SIM card?
Not if your plan already includes the USA at little or no extra cost. If your network charges a daily fee, pay-as-you-go rates or an expensive pass there, a US eSIM or SIM for data usually costs less.
Can I buy an eSIM for the USA before I travel?
Yes. You buy it online, install it at home on Wi-Fi, and it starts when it first connects in the US. Your phone must support eSIM and be unlocked.
How much is roaming in the USA from the UK?
It depends on your network. As of October 2026, Sky Mobile charges £2 a day, Three £7 a day (£8 for customers who joined from 18 December 2025) on plans without roaming built in, O2 £7 a day with its Travel Bolt On, Tesco Mobile 1p per MB, SMARTY 10p per MB within a £45 limit, Lebara £5 for 4 GB with an add-on, and giffgaff 20p per MB unless you buy a USA add-on. Check your own plan before you fly.
Facts checked on 20 October 2026 against our catalogue; our UK network guides (checked on 14 October 2026 against each network's own pages); Three's, Vodafone UK's and O2's roaming pages; Telstra's, Optus's and Vodafone Australia's roaming pages. Exchange rates: European Central Bank, 19 October 2026. Check your own network's US charges before you travel.