Key takeaways
- 81% of the plans in our catalogue can be topped up: 1,292 of 1,589. The other 19% cannot, and you only find out when you run out.
- Top-up support is a property of the wholesale carrier, not the destination. One supplier allows it on all 509 of its plans; three others allow it on none.
- The pattern is cruel: the destinations people stay in longest are the worst. Hong Kong 0%, Japan 15%, South Korea 22%, Australia 28%.
- Bigger plans are less likely to be top-uppable, not more, 65% at 20 GB and above, versus 87% at 1 GB.
- If a plan cannot be topped up, running out is not a disaster: you buy a second plan. It is a new QR code and a new install, not a lost trip.
“Can I add more data if I run out?” is one of the most common questions we get before purchase, and the honest answer is: usually yes, but it depends on the plan, and not in a way you would guess.
So we counted. This is every one of the 1,589 live plans in our catalogue, checked against the top-up flag each supplier publishes. Every number can be verified on the plan pages of this site.
What a top-up actually is
A top-up adds data to the eSIM that is already installed on your phone. Nothing new to scan, nothing new to install, and your existing profile keeps working. That is the whole appeal: you do it from a cafe in ten seconds.
When a plan does not support top-ups, the alternative is to buy a separate plan for the same destination. That works fine, but it is a different eSIM: a new QR code, a new profile added to your phone, and you switch your data line over to it. Perfectly survivable, just not one tap.
How many plans can be topped up
| Plans | Share | |
|---|---|---|
| Can be topped up | 1,292 | 81.3% |
| Cannot | 297 | 18.7% |
| Total published plans | 1,589 | 100% |
Four out of five is a comfortable-sounding number until you notice that the 19% is not spread evenly. It is concentrated in exactly the places you would least want it to be.
It follows the carrier, not the country
Sort by supplier and the split is almost binary. Carriers either support top-ups across their whole range, or not at all:
| Supplier | Top-up allowed | Rate |
|---|---|---|
| Sparks | 509 / 509 | 100% |
| 3 | 79 / 80 | 98.8% |
| eSIMGo | 267 / 275 | 97.1% |
| NextLink | 167 / 177 | 94.4% |
| Airalo | 232 / 254 | 91.3% |
| Ubigi | 38 / 99 | 38.4% |
| TSimTech | 0 / 94 | 0% |
| RoamVault | 0 / 65 | 0% |
| IIJ | 0 / 7 | 0% |
This is the same structural story as data breakout: what looks like a per-country difference is really a decision made once, by a wholesale carrier, and inherited by every destination it serves.
Which destinations are worst
Counting only plans sold for one specific country, with at least eight plans available:
| Destination | Plans that can be topped up | Rate |
|---|---|---|
| Hong Kong | 0 / 9 | 0% |
| Japan | 4 / 26 | 15.4% |
| South Korea | 2 / 9 | 22.2% |
| Australia | 5 / 18 | 27.8% |
| China | 8 / 21 | 38.1% |
| Mexico | 4 / 10 | 40.0% |
| Nepal | 4 / 9 | 44.4% |
| Singapore | 8 / 16 | 50.0% |
| Indonesia | 8 / 15 | 53.3% |
| Philippines | 6 / 11 | 54.5% |
And the other end, where every single plan supports it: the Dominican Republic (14/14), Turkey (12/12), Qatar, Panama, Egypt, Sri Lanka, South Africa, Paraguay and Nicaragua. All 100%.
The awkward part: East Asia is where travellers most often stay two or three weeks, and it is exactly where top-ups are least available. Hong Kong, Japan, South Korea and China are four of the five worst destinations on this list. If you are going there for longer than a week, size the plan properly at purchase instead of counting on adding more later.
Bigger plans are less likely to be top-uppable
This one surprised us. The intuition is that a large plan is a premium product and would come with more flexibility. The data says the opposite:
| Plan size | Can be topped up | Rate |
|---|---|---|
| 1 GB or less | 179 / 206 | 86.9% |
| Over 1 GB, up to 5 GB | 533 / 624 | 85.4% |
| Over 5 GB, up to 20 GB | 434 / 533 | 81.4% |
| Over 20 GB | 146 / 226 | 64.6% |
The likely reason is not policy but composition: the large-volume tiers are disproportionately supplied by the carriers that do not offer top-ups at all. It is the carrier effect showing up again, in a different cut of the same data.
What to do about it
Before you buy, check the plan page. Top-up support is listed with the other plan details. If you are going somewhere on the bad end of that table for more than a week, buy one size up rather than planning to extend.
If you run out and the plan supports it, top up from the Check Order page. The data lands on the eSIM already in your phone.
If you run out and it does not, buy a second plan for the same destination. You will install a second eSIM profile and switch your data line to it. Most phones hold several. It costs an extra plan, not an extra device, and it is the reason running out is an annoyance rather than an emergency.
FAQ
Does a top-up extend the expiry date too?
It depends on the plan. Some extend validity, some only add data to the existing window. The plan page states which. If your days are running out rather than your gigabytes, read that line carefully.
Can I top up before I run out?
Generally yes, while the plan is still valid. Waiting until you are at zero in a foreign country with no data to buy with is the situation worth avoiding. Top up while you still have a connection.
Do I need to scan a new QR code for a top-up?
No. That is the entire point of a top-up: it applies to the profile already installed. A new QR code means you bought a new plan, not a top-up.
Why can’t Japan plans be topped up?
Because the carriers behind most of our Japan inventory do not offer it, including IIJ, the one that gives you a genuine Japanese IP address. Four of our 26 Japan plans support top-ups; the rest do not.
Is a top-up cheaper than buying another plan?
Usually, but not always, and the gap is small. The real advantage is convenience: no second install, no switching lines, no second QR to keep track of.
Which suppliers allow it, by name
Because top-up follows the carrier, the useful question is not whether Thailand supports top-ups but which supplier is behind the plan you are about to buy. Every plan page names its supplier, so this is checkable before you pay.
| Supplier | Plans in our catalogue | Top-up supported |
|---|---|---|
| Sparks | 509 | All of them |
| eSIMGo | 275 | 97% |
| Airalo | 254 | 91% |
| NextLink | 177 | 94% |
| 3 | 80 | 99% |
| Ubigi | 99 | 38% |
| TSimTech | 94 | None |
| RoamVault | 65 | None |
| IIJ | 7 | None |
Two suppliers account for most of the problem. TSimTech and RoamVault publish 159 plans between them and not one can be topped up. Ubigi is the awkward middle at 38%, and that is the case where you have to read the individual plan page rather than rely on the brand.
The seven destinations where no plan can be topped up
For most countries you have a choice: some plans support it, some do not. For these seven, every plan we currently sell comes from a supplier that does not offer top-ups at all, so there is no option to pick.
- Cambodia (4 plans), Macau (4), Montenegro (4) and Vietnam (4): small single-supplier ranges.
- Thailand (5 plans): RoamVault and True, neither of which supports top-ups.
- Malaysia (7 plans): RoamVault and U Mobile.
- Hong Kong (9 plans): RoamVault and TSimTech.
If you are going to one of these, the decision is made for you: buy the size you need for the whole stay, because there is no adding to it later. Our data sizing guide is worth ten minutes before you pick a number, and overshooting by a few gigabytes costs less than installing a second eSIM in a hotel lobby.
The reverse also exists. Turkey, the United Kingdom, Taiwan, Sri Lanka, South Africa, Tanzania, Tajikistan and Venezuela are at 100%: every plan we list for them can be extended. In those markets you can comfortably buy small and add data if the trip runs long.
How do you check before you buy?
Every plan page on this site states it directly, so this takes about ten seconds and does not require trusting any of the numbers above.
- Open the plan page for the destination and size you want.
- Find the top-up field in the specification block, next to data, validity and hotspot.
- If it says top-up is not available, decide the full trip size now rather than later.
- If you are torn between two plans at similar prices, the one that can be extended is worth a small premium on a trip whose length you are not sure about.
The supplier name is on the same page. If it is TSimTech, RoamVault or IIJ, you already know the answer without reading further.
What happens if you run out anyway?
Less than people fear. You buy a second plan for the same destination and install it, which takes a few minutes on hotel Wi-Fi and gives you a second eSIM profile sitting alongside the first. Your phone can store both; you switch the data line to the new one and carry on.
The real cost is not money, it is doing it at the wrong moment: in a taxi queue, on 2% battery, or somewhere with no Wi-Fi to download the profile over. That is the argument for sizing generously on a plan that cannot be topped up, not for paying more per gigabyte.
Check top-up support before you buy
It is listed on every plan page, alongside data, validity, hotspot and breakout country.
Counted from our live catalogue on 7 September 2026: 1,589 published plans, 1,292 supporting top-ups. Inventory changes; the plan page is always the source of truth.
Related: the companion count of where your traffic actually exits, which country IP your travel eSIM shows. Sizing a plan you cannot extend is easier with how much data you need, and for stays over a month see 30, 60 and 90-day plans compared.