The word "unlimited" is doing a lot of heavy lifting in the travel eSIM market right now. It appears on pricing pages, in App Store listings, and across social media ads targeted at people who just booked a flight. It sounds generous. Reassuring, even. The reality is considerably less glamorous.

In the vast majority of cases, an unlimited eSIM plan delivers full-speed data only up to a certain threshold — often somewhere between 500 MB and 5 GB, depending on the provider and destination. Once you cross that line, your connection is throttled. Not cut off entirely, but slowed to a speed that makes modern smartphone use genuinely painful.

Holafly, one of the most widely recognised unlimited eSIM providers, does not explicitly state a speed cap in its core marketing copy. You have to dig into the fine print to find fair-use clauses that describe speed reductions after a usage threshold. That is not an accident. Speed caps buried in terms and conditions are a deliberate marketing choice, not an oversight.

Here's the uncomfortable truth: there is no such thing as a truly unlimited mobile data plan for travellers. Local network operators cap what resellers can offer. Infrastructure has costs. Somewhere in the chain, there is always a limit. The only honest question is whether that limit is shown to you before you buy.

[https://d8j0ntlcm91z4.cloudfront.net/user_3BfnZ5YUh9WpBCxk43aVLselMqF/hf_20260710_081044_24b2fb80-f05f-4496-abeb-6a9a374b00e9.png — Side-by-side infographic: left panel shows a magnifying glass hovering over dense T&C fine print with a throttling clause highlighted in red; right panel shows Kolet's clean, simple pricing page with plan sizes and speeds stated upfront. Caption: "Spot the difference."]

Throttling is a technical process where a network operator or reseller deliberately reduces your data transfer speed after you hit a usage trigger. Instead of the 20–300 Mbps you would expect from a standard 4G or 5G connection, you are suddenly operating at somewhere between 128 kbps and 512 kbps. For context, that is roughly equivalent to early 2G speeds, the kind that were considered slow in 2005.

At 512 kbps, Google Maps takes several seconds to load a single tile. A WhatsApp voice call becomes choppy and drops. Streaming video is not realistically possible. Even basic tasks like loading an email with an attachment or refreshing an Instagram story start to feel like a small act of endurance.

Providers don't lead with this information for an obvious commercial reason: "Unlimited data, full speed up to 3 GB then throttled to 512 kbps" does not convert as well as "Unlimited data." Marketing teams know this. So the speed cap migrates to a fair-use policy document, buried several clicks away from the purchase button, written in the kind of language that is technically accurate but practically invisible.

The phrase to watch for is "fair use policy" or "FUP." It appears in the terms of most unlimited travel eSIM providers. It is the contractual mechanism that allows them to throttle your connection while still calling the plan unlimited. Technically correct. Functionally misleading.

Some providers also apply throttling at a network level rather than an account level, meaning the cap can kick in without any notification to you at all. Your phone just gets slower. You assume it is the local network. You do not connect the dots until you are standing in an airport trying to figure out which gate your connecting flight is at.

[https://d8j0ntlcm91z4.cloudfront.net/user_3BfnZ5YUh9WpBCxk43aVLselMqF/hf_20260710_081148_0f58cec5-55c5-4114-a38b-5dc21295ddb4.png — Illustrative speed comparison graphic: a horizontal bar chart showing real-world tasks (Google Maps, WhatsApp call, video streaming, email) against minimum required speeds, with a red marker at 512 kbps showing which tasks fail at throttled speed. Clean, data-driven visual.]

You land in Tokyo after a 12-hour flight. You clear immigration, activate your unlimited eSIM plan, and spend the first day exploring freely. Maps load instantly. You FaceTime home from Shibuya crossing. Everything works. You are sold on the product.

Day three. You have used about 4 GB navigating, sharing photos, and keeping up with work messages. You do not notice the exact moment the throttle kicks in, but by mid-morning your maps are loading in fuzzy, incomplete tiles. You open Citymapper to find a subway connection and it stalls on the loading screen. You try Google Maps as a backup. Same result.

You are standing at an intersection in Shinjuku, late for a reservation, with a smartphone that is technically connected but practically useless for navigation. The plan is still showing "active." The data counter is still ticking. You are not out of data. You are just throttled.

This is the throttling trap. It is not a dramatic failure. No error message. No warning. Just a connection that quietly degrades until it no longer serves the purpose you bought it for.

[https://d8j0ntlcm91z4.cloudfront.net/user_3BfnZ5YUh9WpBCxk43aVLselMqF/hf_20260710_081247_8b8d762e-be5d-4e0c-aecd-dec7d82b4d7f.png — Street-level photo of a traveller staring at a loading spinner on their phone screen at a busy urban intersection, visually frustrated. Warm, relatable, slightly ironic tone. No text overlay needed.]

This section exists to make one point, clearly: throttled data is not a minor inconvenience. It is a product failure dressed up as a feature.

When a provider sells you an unlimited plan and throttles you at 3 GB, you have effectively purchased a 3 GB plan with extra steps. The difference is that a 3 GB plan is honest about what it delivers. An unlimited plan with a buried FUP is not.

The global travel eSIM market is worth $1.75 billion in 2026. That is a lot of people paying for connectivity they are not actually getting.

[https://d8j0ntlcm91z4.cloudfront.net/user_3BfnZ5YUh9WpBCxk43aVLselMqF/hf_20260710_081254_4332179e-aa69-44a0-a713-23290894ec24.png — Minimalist graphic: a brick wall labeled "Your Speed Cap" with a small sign reading "fair use policy, clause 7.3." Slightly satirical, on-brand for Kolet's irreverent tone.]

The cleaner model is also the simpler one. You buy a specific amount of data. You use it at full speed. You know exactly when it runs out. No throttling, no fair-use traps, no surprises at 2 AM in a city where you do not speak the language.

This is how Kolet works. Plans range from 1 GB to 20 GB, valid for 30 days from your first connection, covering 188 destinations on a single eSIM you never have to reinstall. Every megabyte you purchase is delivered at full 4G or 5G speed. There is no threshold after which Kolet quietly degrades your connection. The speed you get on the first megabyte is the same speed you get on the last one.

Pricing starts at €3.99 for 1 GB in Europe and goes up to €99.99 for 20 GB in higher-cost destinations. You see the exact price before you buy. You see it again before every international call through Kolet's internet-based calling feature, which launched in March 2026. No surprises is the product design principle, not just the marketing copy.

The other structural difference is what happens to unused data. With a traditional eSIM plan, whether unlimited or fixed, data that expires is simply gone. Kolet converts unused data to Koins at expiry. One euro equals 100 Koins. Those Koins sit in your wallet and apply toward your next plan, a top-up mid-trip, or international calls. If you buy a 5 GB plan and use 3.5 GB, the equivalent value of 1.5 GB does not vanish. It comes back to you.

For frequent travellers who collect Air France or KLM points, Kolet also integrates directly with Flying Blue. You earn 10 miles per euro spent, and you can pay with miles accumulated from flights. Several airline partners including Air France, KLM, and Transavia offer passengers 1 GB free on select routes, credited directly to the Kolet wallet.

Kolet is also, as of January 2026, the only major travel eSIM provider with B Corp certification. The score is 99.7 out of 200. Holafly, Airalo, and Saily are not B Corp certified. B Corp status is not a marketing badge. It is a third-party accountability standard that requires verified performance across governance, workers, community, and environmental impact. For a category that competes largely on price and convenience, it is a meaningful differentiator for travellers who care where their money goes.

The simple rule: if a plan calls itself unlimited and does not tell you the speed cap before you buy, assume the cap exists and plan accordingly. If a plan tells you exactly how many gigabytes you get and guarantees full speed throughout, you are working with honest infrastructure.

You are about to spend a non-trivial amount of money on a trip. The data connection that supports navigation, communication, translation, and work should not be a guessing game.

[https://d8j0ntlcm91z4.cloudfront.net/user_3BfnZ5YUh9WpBCxk43aVLselMqF/hf_20260710_081305_bcae638a-ee86-47a9-85f6-529679e410da.png — Clean product visual: Kolet app screen showing a 5 GB plan with full-speed indicator, Koins wallet balance, and a "Top up" button. Soft travel backdrop, warm lighting. No throttling language needed — the clarity of the UI makes the point.]