Postmarks / eSIM education

The eSIM curriculum

Thirty short lessons, from "what even is it" to "fixing it on a ferry". Read in order if you're new; jump straight to your problem if you're not.

30 lessons · ~2 hours total

Skip class, take the compatibility test →
Stage

Basics

START HERE · Nº 01-06
What is an eSIM? A plain-language guide

Nº 01

What is an eSIM? A plain-language guide

No jargon. What an eSIM actually is, how it differs from a plastic SIM, and why travellers adopted it first. A plain guide before your next trip.

8 MIN · MARTA KOWALSKA

Nº 02

eSIM vs physical SIM: what actually changes

3 MIN · MARTA KOWALSKA

Nº 03

Is your phone eSIM compatible? The full list

3 MIN · MARTA KOWALSKA

Nº 04

How to install an eSIM in two minutes

3 MIN · MARTA KOWALSKA

Nº 05

Activate before you fly: the pre-flight ritual

3 MIN · MARTA KOWALSKA

Nº 06

Data roaming explained (and why it costs so much)

3 MIN · MARTA KOWALSKA

Before you fly

Nº 07-20
How much data do you need for a week abroad?Keep your number, carry our dataDual SIM done right: home line plus travel dataeSIM on iPhone: step by stepeSIM on Android: step by stepCountry vs regional vs global plans

On the road

Nº 11-24
Topping up abroad without tearsHotspots and tethering on a travel eSIMWhatsApp, iMessage and your eSIMTwo countries, one trip, one eSIMeSIM on cruises and ferriesIn-flight data: myths at 30,000 feetBusiness travel: receipts, VAT and expenses

Fixes

Nº 10-27
What happens when your plan runs outQR code vs one-tap installAPN settings, demystifiedWhy your eSIM shows "No service" (and how to fix it)Battery myths, testedUnlocked vs carrier-locked phones

Deep cuts

Nº 18-30
eSIM security: is it safer than plastic?How eSIMs actually work: the tech behind the tapeSIM for tablets and smartwatchesAfter the trip: should you delete your eSIM?The travel-day checklist

POP QUIZ · TOOL

Will thy phone take an eSIM?

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HOMEWORK, THE FUN KIND

Done reading? Pick a destination and try lesson four for real.

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