eSIMs vs International Roaming vs a Local SIM: The Real Numbers for a Two-Week Trip in 2026

The notification arrives the moment the aircraft touches down at Barcelona El Prat: “Welcome to Spain. Roaming charges apply. You will be charged £8.00 per day.” Fourteen days later, that's £112 before you've made a single call — just for the privilege of using your existing phone number abroad. The passenger in the next seat bought an eSIM the night before departure and paid £16 for the entire fortnight. The gap between these two outcomes is entirely a function of five minutes of research before you fly.

In 2026, there are three main ways to stay connected abroad: international roaming on your existing UK plan, an eSIM purchased and installed before departure, or a physical local SIM from your destination. Each has a different cost structure, a different set of trade-offs, and a different ideal user. This article runs the actual numbers for a typical two-week European trip so you can make an informed choice before you land.

What we're comparing

The modelled trip is 14 nights in a popular European destination — Spain, France, Italy or Greece. We assume typical travel data usage: around 5GB over the fortnight, covering maps, messaging, occasional social media, and light streaming. We also model 50 minutes of voice calls and 100 texts. All prices are in GBP at May 2026 rates.

The three options under comparison:

• International roaming — using your UK SIM abroad. Your home network either charges a daily add-on fee or bills per-use at high rates.
• eSIM — a digital SIM you purchase from a third-party provider and install on your phone before leaving the UK. It runs alongside your existing physical SIM.
• Local SIM — a physical prepaid SIM card bought at a shop in your destination country, swapped into your phone on arrival.

International roaming in 2026

UK travellers lost automatic EU roaming protections after Brexit in 2021. For several years the major networks voluntarily held off reintroducing charges, but those commitments have largely expired. Here is what the main UK networks actually charge for a 14-day European trip in 2026:

• EE: £3 per day (up to 25GB/day). A 14-day “Europe Pass” bolt-on costs £45 for unlimited data. Without any bolt-on, EE charges £4.50 per MB — a catastrophically expensive default if you forget to add one before departure.
• Vodafone: £1.50 per day in Europe Zone 1, capped at £15 per month after ten days. Days 11–14 cost nothing extra. Relatively competitive for short-to-medium trips.
• O2: £3.50 per day (Roam Boost). Standard plans without Roam Boost revert to per-MB billing and become eye-wateringly expensive on any modern data usage.
• Sky Mobile: Included in most Sky plans for selected European destinations. Effectively free for existing Sky Mobile subscribers within the covered country list.
• Three (Go Roam): Included in most Three plans for 71 countries. You simply use your existing UK allowance — no daily charge, no add-on to buy, no action required. This is by far the best outcome for roaming.
• Smarty, iD Mobile and other MVNOs: Policies vary significantly; some charge £2–£5 per day, others include limited EU roaming. Check your specific plan before assuming either way.

For 14 days: EE costs £42 at the daily rate (or £45 as a bolt-on). Vodafone costs £15 in total. O2 costs £49. Three costs nothing. The spread across networks is remarkable — and it changes year to year, so check before every trip even if you checked last year.

eSIMs: how they work and what they cost

An eSIM is a digital SIM card embedded in your phone's hardware. Rather than a physical card, it's a programmable chip that can store multiple operator profiles. You purchase a data plan from an eSIM provider, scan a QR code (or use the provider's app), and the plan is installed directly onto your phone. You then activate it when you land abroad.

The key practical advantage: your physical UK SIM stays in the phone and continues to receive calls and texts in the background. You use the eSIM for mobile data, and your UK number remains reachable via Wi-Fi calling or standard GSM if your network supports cross-SIM calls.

Compatible devices include iPhone XS (2018) and later, Samsung Galaxy S20 and later, Google Pixel 3a and later, and most Android flagships from 2020 onwards. Note that the iPhone 15 sold in the United States is eSIM-only — no physical SIM slot at all. Older or budget Android phones may not support eSIM; check your exact model before assuming compatibility.

Representative eSIM prices for a 14-day European trip with approximately 5GB of data, at May 2026 rates:

• Airalo: £11–£16 for a 5GB European regional package (covers 36+ countries).
• Simify: £12 for 5GB Europe.
• Ubigi: £13 for 5GB European coverage.
• Nomad: £14–£19 for 5GB across Europe.
• Holafly: £24 for unlimited data for 14 days (no speed cap, subject to fair-use policy).

Most eSIM plans are data-only — voice calls go via WhatsApp, FaceTime Audio, or Signal over your data allowance. If you need your UK number to ring through (for bank two-factor authentication codes, or calls from people who don't use messaging apps), your UK physical SIM handles that in parallel. On an iPhone, you can set this up explicitly: Settings → Mobile Data → Default Voice Line (UK SIM) / Default Data (eSIM).

Local SIMs: the traditional approach

Buying a physical prepaid SIM card at your destination remains the cheapest raw option. In Spain, a Vodafone Spain or Orange prepaid SIM typically costs €10 and includes 15–20GB of data plus 100 minutes of calls. In France, a Free Mobile or Bouygues prepaid SIM starts at around €10–€15 for a month with generous data. At May 2026 exchange rates, that's roughly £8–£13.

The trade-offs are more significant than they appear:

• Your UK number goes silent. While the local SIM is active as your primary data and calling SIM, calls to your UK mobile go to voicemail. Bank and app two-factor authentication texts arrive on your UK number, not your local one — meaning you either keep swapping SIMs or rely on authenticator apps.
• Setup takes time and local knowledge. You need to locate a shop, which may involve queuing or arriving after hours when shops are closed. Budget 30–60 minutes on day one.
• ID registration is legally required in some countries. France, Italy and Germany all require prepaid SIM purchasers to register with a passport or national ID. Most shops handle this at point of sale, but it adds time and means your data is held by a foreign carrier.
• Physical SIM handling. Removing and re-inserting SIM cards is fiddly, risks damaging the SIM tray, and means you have a UK SIM card floating loose somewhere in your bag for a fortnight.

If you have a dual-SIM phone (hardware dual-SIM slot, or one physical SIM slot plus eSIM support), you can run your UK SIM and a local SIM simultaneously. This removes the “UK number goes silent” problem and makes local SIMs considerably more attractive — especially for longer trips where the price advantage compounds.

The real numbers side by side

Total cost for 14 days in Europe, for a solo traveller with 5GB of data usage:

The gap between the most expensive option with a working connection and the cheapest is around £40 for a solo traveller. For a family of four, each on their own contract with EE or O2, that gap becomes £160 or more — enough to cover several restaurant meals. The hidden cost of defaulting to your home network's standard roaming rates is significant and easy to overlook when you're focused on packing.

Which option wins for your trip

The right answer depends on your existing network, your phone, and your trip length:

• Three Go Roam customer: Use your existing plan. Nothing to buy, nothing to configure. Verify your destination is on the Go Roam list and travel.
• eSIM-compatible phone, not on Three: An eSIM is almost always the best combination of price, convenience and functionality. Buy a plan from Airalo or Simify a few days before departure, install it at home on Wi-Fi, and your UK number continues to receive texts in the background. The setup takes ten minutes and you never queue at an airport kiosk.
• Long trip of three weeks or more, or budget-first traveller: A local SIM makes sense if you have a dual-SIM device. The upfront hassle is worth it when the savings are larger and the dual-SIM setup keeps your UK number reachable.
• Short trip of one to three days, Vodafone customer: At £1.50 per day, Vodafone's roaming rate is competitive enough that the time cost of setting up an alternative isn't worth it for a weekend trip.
• Everyone else: Check your network's current roaming policy before every trip. EE and O2's charges have changed multiple times since 2021 and are easy to miscalculate — never assume last year's arrangement still applies.

Practical checklist before you go

• Confirm whether your phone supports eSIM — search your model name plus “eSIM” if you're unsure. iPhones from XS (2018) onwards and most Android flagships from 2020 onwards do.
• Buy and install the eSIM at home before you leave. Installation requires a stable Wi-Fi connection; some plans also require a brief identity verification step that's easier to complete before you're in an airport queue.
• If using an iPhone, go to Settings → Mobile Data and set your UK SIM as the default for calls and SMS, and the eSIM as the default for mobile data. Enable Wi-Fi Calling on your UK SIM (Settings → Phone → Wi-Fi Calling) so your UK number rings through even when data is on the eSIM.
• If buying a local SIM, check your destination's ID registration requirements before arrival. France and Italy require passport details; most shops handle registration on the spot but it takes time.
• Use our timezone converter to keep track of meeting times across zones — especially relevant if you're keeping a UK work schedule while travelling.

Connectivity is one of those travel costs that runs on autopilot if you don't deliberately intervene. The principle is the same as travel money: the difference between choosing the right option and the wrong one is meaningful, and the research takes minutes. We covered the equivalent gap in payment methods in our travel money guide— the pattern is consistent. A small amount of planning before departure reliably saves a disproportionate amount of money once you're there.