Guides · 5 min read
Ran out of data mid trip: top up or buy a new eSIM?
The eSIM says zero and you are three days from home. There are two ways back online, and they are not equal. A top up adds data to the plan you already have, on the same profile, with no reinstall. A new plan is a second eSIM from the same seller or any other, installed alongside the first. The top up is quicker. The new plan is often cheaper. And on roughly two thirds of the plans we track, the top up is not available at all, which settles the question before it starts.
First, can you top up?
Top up support is a seller decision, and it is nearly all or nothing. Across the 61 sellers we compare, some support top ups on every plan, some on none, and a number of them on most. The split as we read it in September 2026:
| Top up support | Sellers |
|---|---|
| Every plan | ASIMGO, Breeze, Cellesim, Esimatic, Flysimio, HiRoaming, MyEsimGlobal, RoameSIM, Soovia, Telekonek, nadanada |
| Most plans | SparkRoam (99 percent), eSIMfly (99 percent), Govora (99 percent), eSIMzio (98 percent), MegaEsim (97 percent), Simbye (95 percent), Lumbus (85 percent), AirPlans (83 percent), Wanderly (79 percent), MobiMatter (73 percent) |
| Some plans | Skyalo (53 percent), Roamix (8 percent) |
| No plans | Airalo, AloOui, AlpineSIM, BuyUKeSIM, ByteSIM, CloudOn, CocoRoam, Connect Me Guru, FlyEsim, GigSky, GigaPanda, Gigago, Mobal, Nomad, OVOSIM, PikaSim, Saily, Superalink, Textr, Travel eSIM, Yatelo, Yesim, abesteSIM, eSIM Hero, eSIM4Travel, eSIMCard |
Some of the sellers in the no row do offer add ons through their apps in practice, but treat them as new plans rather than top ups on the original profile. The effect is the same as installing a second eSIM. We record the top up flag on every plan in our tables, so you can see before buying whether the escape hatch exists.
If you can top up
- Get on WiFi.
- Open the seller's app or account page, find the active plan, choose top up or add data.
- Pick the amount. Check the price per GB against the original plan; top ups are frequently dearer per GB, and sometimes cheaper.
- Check what happens to validity. Most top ups inherit the original expiry. If the plan expires tomorrow, a 5 GB top up expires tomorrow too.
- Pay. Data appears on the existing profile in under a minute. No QR code, no settings change.
The convenience is real. Nothing to install, nothing to switch, and if the seller's app is any good the whole thing is ninety seconds.
If you cannot, or the top up is expensive
Buy a fresh plan, from anyone. Your phone holds several eSIM profiles and switching between them is a single setting.
- On WiFi, open our page for the country you are in and filter to the size you need for the rest of the trip. The cheapest real option is the top row.
- Buy, install from Settings (not the Camera app), and turn on data roaming for the new line.
- Set the new line as mobile data. iPhone: Settings, Cellular, Cellular Data. Android: SIM manager, Mobile data.
- Leave the empty eSIM in place, or turn its line off. It does no harm either way.
The cheapest plans for a country are frequently from a seller you have not heard of, and that is exactly the situation where a comparison site earns its keep. In September 2026 a 3 GB plan to finish a trip averaged around $12 across all sellers in our data, and under $2 from the cheapest in Thailand, Turkey or Spain.
Comparing the two in one minute
Two numbers. The top up price per GB, from the seller's app. The cheapest fresh plan price per GB for the same size, from our country page. Take the lower one, unless the top up is within a dollar or two, in which case take the top up for the convenience. If the original plan expires in a day or two and the top up inherits that expiry, the fresh plan wins regardless, because you are buying days as well as gigabytes.
How many eSIMs can the phone hold?
More than you will need on one trip. Recent iPhones store eight or more profiles with two active at once. Samsung and Pixel phones store several. A second travel plan alongside an empty one is normal, and the only housekeeping is deleting the expired profiles when you get home so the list stays readable.
Bridging the gap
If you are near the end and the numbers do not justify either option, WiFi carries you. Cafes, hotels and most public transport in tourist areas have it. Download the offline map before leaving each WiFi spot, and put the phone on Low Data Mode so it stops trying. A last day on WiFi is not a hardship; a last day on the ship network at $6 a megabyte is.
Why it ran out, and how to stop the sequel
Nearly every mid trip empty we hear about is background traffic rather than use. Photo backup found the hotel WiFi weak and switched to mobile data. An app updated. A feed preloaded an hour of video. The fixes take two minutes and they are the same on every trip:
- Photo backup, app updates and cloud sync to WiFi only.
- WiFi Assist (iPhone) or Adaptive WiFi (Android) off, so weak WiFi does not silently become mobile data.
- Low Data Mode (iPhone) or Data Saver (Android) on for the travel line.
- Check usage on day two. iPhone: Settings, Cellular, scroll to the eSIM's usage. Android: Settings, Connections, Data usage. If day two is over a third of the plan, act then, not on day six.
When choosing the next plan: if the seller does not support top ups, buy one size above your estimate. The extra few dollars is cheaper than a second plan bought in a hurry. If they do, buy at your estimate and top up if needed. Our tables show the top up flag on every plan.
A word on daily unlimited plans
If the plan that ran out was a daily unlimited plan, it has not really run out. It has been throttled until the reset, usually midnight local time. Check the time, and if the reset is a few hours away, WiFi bridges it. If the throttle is unbearable and the reset is far off, a fresh small plan from another seller for the remaining days is usually the cheaper answer than a second unlimited plan. Our guide to fair use caps covers what the throttle actually feels like.
Questions people ask
Can I top up any travel eSIM?
No. Across the plans we track, top ups are supported on every plan from some sellers and on none from others, with a few in between. Roughly a third of live plans can be topped up. The plan page says, and our comparison tables carry a top up flag for every plan.
Is a top up cheaper than a new eSIM?
Not always. Top ups are priced for convenience and often cost more per GB than the original plan. A fresh small plan from a different seller can be cheaper, and installs in two minutes over WiFi. Compare both before paying.
How do I top up without data?
Connect to WiFi, open the seller's app or website, find the active plan and choose top up or add data. Payment goes through, and the extra data appears on the existing profile within a minute. No new QR code, no reinstall.
Will a second eSIM conflict with the first?
No. Phones hold several profiles. Install the new one, set it as the mobile data line, and leave the empty one in place or switch it off. The two never interfere.
Does unused top up data carry over?
It follows the plan's validity. A top up on a plan that expires on Friday also expires on Friday, on most sellers. A few extend validity with a top up; the plan page says. Do not top up a plan that is about to expire unless it does.
How do I stop this happening again?
Buy the size above your estimate on plans that cannot be topped up, set photo backup and app updates to WiFi only, and turn on Low Data Mode or Data Saver for the travel line. Most mid trip empties come from background traffic, not from use.
Compare plans for the places in this guide
236,811 plans from 61 sellers, ranked by real price per GB, with prices checked against the shops themselves.
