What is FUP on an eSIM and why it matters

When you see an eSIM plan advertised as "unlimited Japan / €24.90" you'd think you can binge Netflix for 5 days straight. The reality is that almost all of those plans have a FUP (Fair Use Policy) limiting real data to 1-2 GB per day before dramatically dropping the speed. If you understand how FUP works, you'll make better buying decisions and stop overpaying for an "unlimited" that isn't really unlimited.

What FUP is

Fair Use Policy is a technical clause that lets the carrier limit speed or data when you exceed a threshold. In tourist eSIMs, there are two types:

Speed-based FUP

The plan has "unlimited data" but after X GB they throttle the speed to something very slow (typically 256-512 kbps). This is enough for WhatsApp and emails, not for smooth Maps or video.

Real example: Holafly Japan "unlimited", €24.90 for 5 days.

• Fine print: 1 GB/day at normal speed. After that, 256 kbps.
• 256 kbps = 32 KB/s. A Google map takes 10-15 seconds to load. Video, impossible.

Cutoff FUP

Some "unlimited" plans simply cut off service once you exceed the threshold. You're left to top up or wait for the next day.

Less common but exists. Read the terms before buying.

Why providers do it

Physics: antennas have limited capacity. If every MVNO user pulled 50 GB/day, networks would collapse. FUPs are the tool to prevent a "saturating" user from ruining the experience for others.

It's legitimate. The problematic part is deceptive marketing that sells "unlimited" without highlighting the FUP.

How to spot FUP in "unlimited" plans

Steps we take when comparing providers:

1. Search for the phrase "fair use" in the plan's terms and conditions.
2. Look for numbers: "after X GB", "high-speed data", "throttled to". If they appear, there's FUP.
3. Compare the FUP GB to your needs:
   • 1 GB/day in normal tourist zone: insufficient if you'll use Maps actively.
   • 2 GB/day: enough for average tourist use.
   • 3 GB/day: comfortable, plenty for normal use.
   • No visible FUP: read carefully or assume there's one at 1-2 GB/day.

Common FUPs (May 2026)

Some providers are honest and publish these limits; others hide them. If you don't see it on the product page, assume the FUP exists.

Why this matters in practice

Case 1: classic tourist

You're going to Japan 7 days, you want data for Maps + WhatsApp + some Instagram photos.

• You need: 5-7 GB for the whole week (≈ 1 GB/day).
• Holafly "unlimited" plan: €24.90. Their FUP is 1 GB/day → you barely make it every day. You'll be frustrated looking for ramen because Maps runs slow.
• Standard 7 GB / 30-day plan: €8-10. You're at full speed all the time, no surprises.
• Difference: pay double for a worse experience.

Case 2: digital nomad

You're working remote from Bali for a month. You need stable Zoom video calls, downloads, GitHub.

• You need: 50-80 GB per month at high speed.
• "Unlimited" plan: ✅ Could work if FUP is 2-3 GB/day (totaling 60-90 GB/month).
• Standard 100 GB / 30-day plan: ~€30, no FUP, full speed always.
• If your "unlimited" provider charges under €25/month with FUP at 2+ GB/day, it's a valid option.

Case 3: light traveler

Weekend in Lisbon, you only need Maps.

• You need: 1-2 GB total.
• Unlimited plan: completely unnecessary, you waste €15-20 on marketing.
• Local 1-3 GB plan: €3-5, plenty and at full speed.

Beyond FUP: marketing tricks

Other common deceptions in tourist eSIMs:

"Unlimited 5G" with cap

Some sell "unlimited 5G in USA" but the FUP is 5 GB of 5G then drops to 4G. For a tourist, T-Mobile USA 4G is perfectly fine, so the difference is academic. But the marketing is misleading.

"Premium data" vs "Economy data"

Some providers internally split data into "premium" (the first X GB) and "economy" (after). The "economy" ones are limited. If you see this in the plan, check the terms.

"Up to X GB" with no commitment

Sneaky phrase. Means: the plan may reach X GB if the network isn't saturated and if you're not "using too much". In practice, often half.

When to pick a plan with strict FUP

Only in these cases:

1. Your usage is low and predictable: normal tourism, Maps + WhatsApp + some social. You'll use 500-800 MB/day and the 1 GB/day FUP is plenty.
2. You'll be on hotel Wi-Fi a lot: modern hotels have decent Wi-Fi. The eSIM only fills gaps.
3. The price compensates: if an "unlimited" with FUP costs less than an equivalent standard plan (rare, but happens), it makes sense.

When to avoid "unlimited" plans with FUP

Almost always. The honest exception is the list above. For any other profile:

• Reloadable standard plan gives you more flexibility for less money.
• You know exactly how many GBs you have and at what speed.
• You can reload in 30 seconds if you run short.
• No mid-trip surprises.

How we do it at eSIM Ahora

We don't sell unlimited plans with hidden FUPs. We sell plans with clear GBs (3, 5, 10, 20, 30) at full speed to the last MB. If you run short, you can reload the same eSIM for €3-4 more in under a minute.

This is more expensive for us to operate but fairer and more transparent for the traveler. And in practice, it works out cheaper — because you're not paying the margin of misleading marketing.

See plans with clear data →

Final recommendation

• Read the fine print of any "unlimited" plan before buying. If you don't find the FUP, assume it exists at 1-2 GB/day.
• For normal tourist trips (1-2 weeks), reloadable plan with 5-10 GB is the most sensible.
• Only "unlimited" plans with FUP ≥ 2 GB/day and competitive price merit consideration — and even then, a standard plan is usually better.
• Marketing in this sector is aggressive. Always compare by GBs and FUP, not by the word "unlimited" in caps.

Calculate how many GBs you need for your trip →