Most travel eSIMs are sold as packages: a fixed bucket of data with a fixed expiry. If you don't burn through the bucket before the expiry hits, the carrier keeps the rest. From the carrier's view, that breakage — the gap between what you bought and what you actually used — is pure margin. From your view, it's the equivalent of throwing away a third of every pre-paid lunch.
This piece is a closer look at why expiry-based pricing is so widespread, what it actually costs the average traveler, and how a no-expiry, per-megabyte billing model removes the math entirely.
Why every travel eSIM has an expiry
The expiry date isn't there for technical reasons. The eSIM profile itself doesn't decay; the SIM doesn't physically wear out; the partner network doesn't need to free up something. Expiry exists because of revenue predictability.
When a carrier sells you 10GB for 30 days, they assume — based on a decade of usage data — that you'll consume between 4GB and 7GB. The remaining 3–6GB is the bet. If you under-use, the carrier wins. If you over-use, you're forced to buy a new pack, and the carrier wins again. Either way, the per-customer revenue is bounded, predictable, and detached from your actual data consumption.
What expiry actually costs — three real-world cases
Let's run the numbers on three common travel patterns. We'll use a sample 5GB / 30-day pack at $15 (typical mid-tier travel eSIM) and compare to per-MB pay-as-you-go billing, where you pay only for the data you actually use.
| Profile | Trip length | Actual data used | 5GB pack | Pay per MB ($0.0021/MB) | Savings |
|---|---|---|---|---|---|
| Weekend in Lisbon | 3 days | 650 MB | $15.00 | $1.37 | $13.63 |
| Two weeks in Japan | 14 days | 3.1 GB | $15.00 | $6.51 | $8.49 |
| Month-long Asia trip | 30 days | 7.4 GB | $30.00 (2 packs) | $15.54 | $14.46 |
The pattern is consistent: unless your usage exactly matches the pack size, you pay for absence. The Lisbon traveler pays for 87% of the pack they didn't use. The Asia traveler pays double-pack price because they crossed the expiry by a few days.
For the math behind this, see how much data you actually need — most travelers consistently overestimate how much data they'll use, then buy the larger pack "just in case", and the gap goes to the carrier.
How no-expiry billing changes the math
A pay-per-megabyte eSIM works differently. There's no pack. You top up a balance — say $20 in stablecoin — and the eSIM bills against that balance at the published per-MB rate for whichever country you're in. When you go home, the balance just stays. When you travel again next month or next year, it's still there.
This removes three losses at once:
- Pack-size guesswork. You don't have to predict trip data usage to the gigabyte. You buy any amount, use whatever you use, keep the rest.
- Expiry pressure. A 6-day trip and a 26-day trip cost the same per megabyte. There's no "use it or lose it" deadline lurking in your settings.
- Refill churn. No buying a second 1GB pack at the airport because the first one ran out the day before. The same eSIM keeps working as long as the balance is positive.
The trade-off — and where pack pricing still wins
To be honest about it: pack pricing isn't always worse. There's one specific case where it's the right call:
Heavy-data trips of known length. If you're going on a 2-week trip and you know you'll burn 8GB streaming hotel-room Netflix, then yes — a 10GB / 30-day pack might come out a few dollars cheaper than per-MB at high-rate destinations. The break-even depends on the country's wholesale rate.
For everyone else — bursty usage, multiple short trips a year, light maps-and-messaging consumption, conservative streamers — the no-expiry model wins quietly and consistently.
Three signals that no-expiry is the right model for you
- You travel several times a year, not one big trip. Three weekend trips burn through three separate expiry-clocks if you buy packs. With pay-per-MB you top up once and use it across all three.
- Your usage varies wildly between trips. A Tokyo trip with constant Google Maps + translate is a different beast from a beach week in Crete. Packs force you to overbuy on the heavy side and waste on the light side.
- You hate "managed" pricing. If you read your phone bills and notice things like "$5 daily roaming pass" and feel a small kick of irritation, no-expiry is built for you. The price is per-MB, the per-MB rate is published, the math is yours.
How Roamzy implements this
Roamzy is a single global eSIM. One profile, 193 countries. The per-MB rate for each country is published openly on our country-by-country price page. There's no expiry on the balance, no expiry on the eSIM, no expiry on the data. You top up, you use what you use, the rest sits there until next time.
Top-ups are in stablecoin (USDT) — that part is unusual but it solves a related problem: paying without giving a card to a foreign-billed mobile-network operator. We have a separate write-up on international eSIM guide, which goes into more detail on the cross-border payment side.
The bottom line
Expiry isn't a feature, it's a pricing tactic. It's how mobile carriers turn one trip's purchase into recurring revenue while making the breakage feel like a quirk of geography. For travelers whose actual usage doesn't slot neatly into a 30-day, 10GB envelope, pay-per-MB with no expiry takes the loss out of the equation.
For most people, that's most trips.
If you want to compare specific country rates against your existing carrier's roaming, the prices page is updated daily: our country-by-country price page. If you'd rather see how pay-per-MB compares to a local prepaid SIM, eSIM vs local SIM runs that comparison alongside.
Sources & further reading
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