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Is an unlimited eSIM really unlimited? Understanding FUP
“Unlimited” sounds like the safe choice, but nearly every “unlimited” travel eSIM has a fair usage policy (FUP) that throttles your speed after a certain amount. The “unlimited” part is really unlimited slow data. This isn’t a scam, it’s industry standard. But you should know how it works before you buy.
What FUP actually is
A fair usage policy is the hidden line a carrier draws under an “unlimited” plan. The common shape: you get a high-speed allowance each day, a few GB say, and once you pass it your speed drops hard for the rest of the day, often slow enough that messaging works but video won’t. It resets the next day.
So “unlimited” usually means full speed for the first few GB, then a crawl.
Throttling comes in two flavours, and they feel very different
“Slowed down” actually splits into two kinds worth telling apart:
- A hard speed cap. Once you pass the allowance, your speed is locked to a low number, roughly like dropping back to 3G. It doesn’t matter whether the tower is busy; you’re just that slow.
- Lower priority. You stay as fast as everyone else until the tower you’re on gets congested (a crowded district, an event), and then the system puts you toward the back of the queue behind people who haven’t gone over. When nothing’s busy you barely notice; the moment it’s busy you slow right down.
So two plans can both say “throttled after X GB” while one means slow all the time and the other means slow only when it’s crowded. Carriers do this so a few heavy users can’t hog a whole tower, which is fair enough, but the effect on you is very different.
What that throttled speed can actually do
Plans write the throttled speed as “128 Kbps”, “256 Kbps”, “1 Mbps” — numbers that mean nothing on their own. Turn them into “how much can this move in an hour” and they start to bite. Divide by 8 for bytes per second, multiply by 3,600:
| Throttled to | Roughly per hour | Still works | Already does not |
|---|---|---|---|
| 128 Kbps | 58 MB | Messaging, navigation (5 MB/hr) | Music streaming and everything above it |
| 256 Kbps | 115 MB | Plus music streaming (100 MB) | Scrolling a photo feed (150 MB) |
| 384 Kbps | 173 MB | Plus the photo feed | Video calls (200 MB) |
| 512 Kbps | 230 MB | Plus video calls | YouTube at 480p (260 MB) |
| 1 Mbps | 450 MB | Plus YouTube at 480p | Short-form video (600 MB/hr and up) |
The consumption figures in the last two columns come from the table in how much data you actually need — they are not a second estimate.
⚠️ This is arithmetic, not a promise. It assumes you saturate that speed continuously, which no real network does: signal, cell congestion and the far-end server all take another cut. Read it as a ceiling on a ceiling — anything the table says will not work, works even less in practice.
One line falls out of it: short-form video does not survive any level of throttling, not even the most generous 1 Mbps. Navigation is the opposite — it has a tenfold margin even at a punishing 128 Kbps. Throttling kills moving pictures, not finding your way.
We pulled the throttle clause on all 1,384 daily plans
The table above answers “what can I do once throttled”. It does not answer “what will I be throttled to”. So we pulled the throttle clause off every daily-allowance plan in our upstream catalogue and published it as a dataset (JSON / CSV, snapshot 2026-08-21).
The first thing it shows: of the 187 countries with daily plans, 169 — nine in ten — have more than one throttle speed sitting on the same shelf. Which means “what is the throttled speed in this country” is the wrong question. Same country, same label, more than one answer.
How all 1,384 plans distribute:
| Throttled to | Plans |
|---|---|
| 512 Kbps | 617 |
| 1 Mbps | 456 |
| 384 Kbps | 246 |
| 500 Kbps | 42 |
| 128 Kbps | 18 |
| 256 Kbps | 5 |
One “1GB/Day” label in Japan, four different throttle speeds
Take Japan. More than one plan carries the “1GB/Day” label, and once throttled they run at 256 Kbps, 384 Kbps, 512 Kbps and 1 Mbps — a fourfold spread. Identical label; which one you get depends on which row you happened to tap.
And picking the “local” line hands you the slowest one
This is the least intuitive thing in the dataset. Those Japanese plans do not all route out of Japan: the 384 Kbps ones exit via Hong Kong, the 512 Kbps ones via Singapore, the 1 Mbps ones via Hong Kong.
The only batch that genuinely exits inside Japan is the 256 Kbps one — the slowest on the table.
So a buyer who deliberately picks a local breakout for native routing and lower latency also picks the worst throttle. On this shelf the two quality axes are mutually exclusive, and no plan page tells you so. Which line exits where is in our exit-location database.
An accident worth keeping: a fixed-volume plan that throttles
One row fell out that should not have been there. Canada 75GB 30Days is a fixed-volume plan,
yet it carries a 128 Kbps throttle clause — meaning those 75 GB do not end in a cut-off, they end
in a speed that is barely usable.
We list it rather than drop it, because it breaks a common assumption: FUP is not only an “unlimited” thing. When a plan says “fixed X GB”, it is still worth checking what happens after.
⚠️ Every number here is the ceiling the catalogue claims, not a measured speed. We have not put a real card on these lines and timed them. It answers what the contract says, not what the network does.
How to read a plan’s FUP
When you look at an “unlimited” plan, don’t stop at the word “unlimited.” Look at two numbers: how much high-speed allowance you get (how many GB at full speed per day or per plan), and how slow it goes after that (can you still load a map, can you still message). Those two decide whether it’s actually usable, and they vary a lot between brands. That’s the real thing to compare.
Two travellers, two verdicts
Scenario one: a five-day city trip, and you’re not a heavy user. You use maybe 1GB a day on maps, restaurant lookups, and sending photos. Plenty of “unlimited” plans set their high-speed line at 1 to 2GB a day, which means you never touch the throttle at all. In other words, the “unlimited” premium you paid for is something you never used. Buying unlimited here is paying for headroom you don’t reach.
Scenario two: you’ll binge shows on the train and hotspot for two friends all day. Hotspotting is the hungriest thing you can do. One hour of HD video can burn 1.5 to 2GB, and sharing your connection on top of that, you’ll likely blow past the daily high-speed line every day. Now unlimited earns its place, but pick one with a high threshold and a throttled floor near 1 Mbps, or your afternoons effectively go offline.
The difference between the two isn’t who’s a “better” user. It’s whether you actually hit the line. Most short-trip travellers are scenario one.
So is it worth it
Depends how you use data. If you stay under the daily high-speed threshold, the extra you paid for “unlimited” is wasted, because you never reach the unlimited part. If you’re a heavy user who blows past it daily, unlimited makes sense, but pick one with a high threshold and a usable throttled speed.
soda takes a different line: no “unlimited” you can’t read. You’re billed by actual usage, and at the end of the trip every available combination of plans is compared and the lowest total is applied in retrospect — use a little, pay a little; use a lot and you still never pay more than if you’d picked the right plan upfront. You set your own spending limit, service pauses when you reach it, and your balance never expires. Most people never reach unlimited territory anyway, so they keep what they’d have overpaid. The logic is in why you shouldn’t gamble on a plan, and sizing your own usage is in how much data do you need. To avoid an unlimited plan quietly billing you for the next cycle, see overage and auto-renewal traps. For how each provider words its throttle threshold, the comparison page lays them side by side.
Frequently asked questions
- After an unlimited eSIM throttles me, when does full speed come back?
- Most plans reset daily, so your high-speed allowance refills at midnight (in the plan's time zone). A few share one high-speed total across the whole plan, meaning once it's gone you crawl until the end. Check which kind you have.
- Why is my unlimited plan still crawling at a concert or New Year's countdown?
- That's usually not a broken plan, it's tens of thousands of phones hammering the same few towers. This "deprioritised when busy" effect hits unlimited users hardest, and no plan, however pricey, fixes it. See the concert section in the Korea eSIM guide.
- Once I've used the high-speed allowance, can I top up to restore full speed?
- Some brands let you buy an extra high-speed pack; others make you wait until the next reset. Confirm before you buy. If you regularly need full speed, an unlimited plan that leans on throttling was the wrong pick anyway.
- Unlimited or a clear "X GB per day," which is the better deal?
- Depends on your usage. If you use less than X GB a day, a clearly labelled "X GB per day" is easier to read and usually cheaper; only genuine daily over-users need unlimited. The threshold is what matters, not the word "unlimited."
- Do unlimited eSIMs quietly auto-renew?
- Some do. Unlimited often comes bundled with a recurring plan that bills the next cycle automatically, and it's easy to miss. To avoid bill shock, see overage and auto-renewal traps.