How to tell if a travel eSIM deal is actually good

Divide by the gigabytes, then by the days

EU rules make shops show a price per unit, per kilo or per litre, on many products, precisely so that packs of different sizes can be compared. Data plans deserve the same treatment, but you usually have to do the sum yourself: price divided by gigabytes. A plan with three times the data for twice the price is cheaper per gigabyte, even if its headline number looks worse.

Then check the second number, the days. A large plan that expires before your trip ends is not a bargain, and neither is a huge allowance you will never get through. Estimate what you need first, with our data calculator or the guide on how much data you need, and compare offers only among plans that cover both the gigabytes and the length of the trip.

When the clock starts

This is the condition that turns a cheap plan bought early into a wasted one. Some plans count their validity from the moment of purchase, some from installation, and some from the first time the line connects to a network in the destination. If you are buying during a sale for a trip months away, only the last kind, or one with a long window before activation, makes sense.

Look for the exact wording in the plan details, not in the banner: when validity begins, how many days it lasts once it begins, and whether there is a deadline to start using it. If the offer does not say, ask before paying. A 30-day plan that started ticking the day you bought it is worth nothing on a trip three months later.

Unlimited, and what comes after the word

An unlimited plan can be the right choice for heavy users, but the word on its own is not a description. Read what the conditions say happens after a certain amount of use: whether there is a daily allowance at full speed, what speed you are left with after it, and whether that reduced speed is enough for maps and messaging or only for text.

Check, too, whether the unlimited part covers sharing data with a laptop or another phone, and whether there is a fair use clause that lets the provider cut or slow the line. A fixed plan with a clear number of gigabytes is often easier to judge, because you know exactly what you are paying for and can see it in the phone's data counter, as explained in what happens when your eSIM data runs out.

What the line actually includes

• Data only or a number: a data-only eSIM has no calls or texts of its own. Your usual line can stay on for those, since Apple says an iPhone can use two plans, with one number at a time carrying cellular data.
• Local networks: which operators the plan can use in each country, so you know what to do if one is weak where you are.
• 5G: Apple lists three conditions on iPhone, an iPhone 12 or later, a carrier that supports 5G and a plan that includes it. A 5G phone does not help if the plan stops at 4G.
• Hotspot: Apple notes that Personal Hotspot needs a carrier that supports it and that extra fees may apply. If you plan to connect a laptop or a tablet, the offer should say hotspot is allowed.

If any of these is missing from the description, treat it as unknown rather than included. How calls home work without a number is in calling home with a data-only eSIM, and sharing data with a laptop in using an eSIM hotspot.

Top-ups, refunds and what happens if it fails

Ask what happens when the data runs out. The convenient answer is a top-up that goes onto the same eSIM, so you do not install a second one in the middle of the trip. The less convenient one is a new plan with a new QR code. Our guide on how to top up a travel eSIM explains the difference.

Then read the refund and guarantee conditions before the countdown on the banner hurries you. Under EU rules, online purchases normally carry a 14-day right of withdrawal, and for services it counts from the day the contract is agreed. There are exceptions: for digital content, the EU says you lose that right once supply starts, if you expressly agreed to it. So the useful question is what the shop does if the eSIM does not install or does not connect, and how you ask for help. Spain's European Consumer Centre also recommends reading the terms and paying with a card rather than by bank transfer.

The crossed-out price must be the lowest of the last 30 days

Sales are where the before price matters most. The EU's Your Europe portal says that when a trader announces a price reduction, it has to show the lowest price applied in at least the 30 days before the announcement, so you can judge whether the discount is genuine. In Spain, article 20 of the retail trade law, Ley 7/1996, defines the previous price as the lowest applied to identical products in the 30 preceding days.

That gives you a simple test. Note the price of the plan you want a few weeks before Black Friday, as Spain's European Consumer Centre suggests, and compare it with the crossed-out figure during the sale. If the before price is higher than what you saw, the percentage off is inflated. The same centre reminds you that the offer price must already include taxes and any unavoidable extra costs.

Before paying: your phone has to accept it

No price is good if the eSIM cannot be installed. Apple says eSIM works on iPhone XS, XS Max, XR and later, with exceptions for models sold in mainland China, and Google says Pixel 3a and later can use an eSIM. Other brands vary by model, so check yours on our compatibility page or in how to check if your phone supports eSIM.

The second check is the carrier lock. On an iPhone, go to Settings, General, About and look at Carrier Lock: No SIM restrictions means it is unlocked. Apple says only your current carrier can unlock it, and that to use plans from two carriers the iPhone must be unlocked. Ask your operator before the sale ends, because Apple warns the process can take a few days. More in how to check if your phone is unlocked.

For reference, here is how Snoozim answers the checklist: a data-only eSIM, the QR code by email right after payment, no app or account, validity that starts when it first connects at the destination, hotspot allowed, top-ups on the same eSIM and prices shown per plan in euros.