Explainers · 5 min read
Why your unlimited eSIM slowed down: the fair use caps
The plan said unlimited. By nine at night you cannot load a map. Nothing is broken. You have hit the fair use cap, which is the daily allowance of full speed data that every unlimited travel eSIM has and almost none of them put on the front of the box.
We track 236,973 live plans from 61 sellers. 107,245 of them are sold as unlimited, and we read the fair use terms behind every one, because a plan that slows to 256 kbps after 1 GB is not the same product as one that slows after 3 GB, and neither is the same as the handful that genuinely do not throttle. This is what we found.
The caps, by the numbers
Across the plans that publish a daily allowance, counted in our catalogue in September 2026, four figures dominate:
| Full speed per day | Plans, September 2026 | What it covers in practice |
|---|---|---|
| 500 MB | 9,650 | Maps, messaging, email. Not video. |
| 1 GB | 16,957 | A normal tourist day if you skip video and cloud backup. |
| 2 GB | 14,832 | Comfortable, including some social video. |
| 3 GB | 15,029 | More than most people use. Streaming in the evening is fine. |
| 5 GB or 10 GB | 7,332 | Effectively unlimited for a phone. |
Note that 500 MB and 1 GB together accounted for 26,607 of those plans. That is a lot of unlimited plans where a single hour of video, or one automatic photo backup, uses the whole day's allowance before lunch.
What the throttle actually feels like
The sellers describe the slowed speed in kilobits per second, which nobody has an intuition for. Here is a translation.
- 128 kbps: WhatsApp text works with a delay. Email headers load. Web pages time out. This is slower than the 2G networks of 2005.
- 256 kbps: messaging is fine, maps draw slowly, a web page takes 20 to 40 seconds. Photos will not upload.
- 512 kbps: most apps work if you are patient. Music streams at low quality. Video does not.
- 1 Mbps: genuinely usable. Standard definition video plays. This is the kindest throttle and the rarest.
The most common throttle across the plans we track is 256 kbps. A few sellers do not publish a figure at all, which in our experience means it is at the low end.
Why sellers do this
It is not a trick, or not only a trick. A travel eSIM roams onto a local network, and the local network charges the seller per gigabyte. Unlimited at full speed with no cap would mean a single traveller tethering a laptop through a Netflix weekend could cost the seller more than the plan price many times over. The cap is how they make the maths work. The problem is purely one of disclosure: unlimited in large type, 1 GB in small type, and a speed after that which most buyers never see until they hit it.
Our position is simple. We publish the daily allowance on every unlimited plan in the comparison table, and we price unlimited plans by their daily allowance, not by a total that does not exist. A plan that gives 1 GB a day for seven days is compared as 7 GB. That is the number you can actually use.
When an unlimited plan is the right buy
Daily cap plans suit a particular traveller: someone who uses a steady amount every day and does not want to think about it. If you know you use around 1.5 GB a day, a 2 GB daily plan means you never run out and never get a surprise. Sellers with 3 GB a day caps are generous enough that most people never notice the cap exists.
They are the wrong buy for anyone whose usage is uneven. A city break where you use 200 MB on museum days and 4 GB on the day you upload everything is much better served by a 10 GB pool you can spend however you like. We compared the two models across a two week trip in a separate guide, with the actual plans and prices.
How to see the cap before you buy
- On the seller's site, ignore the headline and open the plan details or terms. Search the page for the words fair, FUP, daily, or kbps.
- If the daily figure is not there, assume it is 1 GB or less. Sellers with generous caps advertise them.
- Check when it resets. Midnight local is the norm. Rolling 24 hours from first use is worse, because your reset drifts later each day.
- Check whether the plan allows a top up. If it does not, a throttled evening is a throttled evening.
Or use our comparison tables, where the daily allowance sits in the data column for every unlimited plan, and the price per GB is calculated from it.
The plans that really do not throttle
A small number of sellers offer unlimited with no daily cap at all, usually on single country plans in places where wholesale data is cheap. They cost more per day, and the network may still slow you if the tower is busy, but there is no clause that cuts you at a set amount. When one of these exists for your destination it shows up in our tables with no daily figure and no throttle note, which is exactly how you spot it.
Rule of thumb: if a plan says unlimited and the price is close to what a 5 GB plan costs for the same country, the daily cap is 1 GB or below. Real headroom costs real money, and the cheap unlimited plans are cheap for a reason.
What to do tonight if you are already throttled
Check the reset time in the plan terms. If it is midnight local, you are a few hours from full speed and WiFi will carry you. If the plan supports top ups, a small one restores full speed immediately on most sellers. If neither, and you need real bandwidth right now, a second eSIM from a different seller installs in two minutes over hotel WiFi and does not interfere with the first. Your phone can hold several. Check the cheapest plan for your country, buy the smallest one that covers the rest of the trip, and switch data lines.
Questions people ask
What does fair use policy mean on an unlimited eSIM?
It is the clause that sets a daily amount of full speed data. Once you pass it, the seller slows the line, typically to somewhere between 128 kbps and 1 Mbps, until midnight local time. The word unlimited refers to the fact that the line does not cut off, not to the speed.
How slow is a throttled eSIM?
Anywhere from 128 kbps to about 1 Mbps depending on the plan. At 256 kbps, WhatsApp text and email still work, maps load slowly, and video, photo uploads and app updates effectively stop. At 1 Mbps most things work, just not video in high quality.
When does the daily cap reset?
Usually at midnight in the local time zone of the network you are on, not your home time zone and not the time you bought the plan. A few sellers reset on a rolling 24 hours from when you first connected that day. The plan terms say which.
Is a 3 GB per day unlimited plan a good deal?
For a heavy user, often yes. 3 GB a day is more than most travellers use, and the plan costs a fixed amount regardless. For a light user it is usually worse value than a 10 GB pool that lasts the whole trip, because you pay for daily headroom you never use.
Why does the eSIM slow down even before the daily cap?
Network congestion, a weak signal indoors, or the eSIM roaming onto a partner network that gives visitors lower priority. Speed on a travel eSIM is always the local network's speed for roaming traffic, which can be a fraction of what a local SIM gets on the same tower.
Can I buy more full speed data after being throttled?
On some plans, yes, as a top up or by buying a second plan. On daily cap plans the usual answer is to wait for the reset. Check whether the plan allows top ups before you buy it, because that is the difference between a slow evening and a slow week.
Compare plans for popular destinations
236,973 plans from 61 sellers, ranked by real price per GB, with prices checked against the shops themselves.
