THE SONET JOURNAL

Postmarks

Notes on travel, data, and saying it well. Thirty short lessons on eSIMs, thirty destination guides, and the tools in between.

Category
Topics
Type
Vietnam by scooter and street stall

GUIDE

Vietnam by scooter and street stall

FEATURED · eSIM EDUCATION

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 READ · UPDATED FEB 2026

Tool · 2 MINUTES

eSIM compatibility checker

Check my phone →

How to install an eSIM in two minutes

ARTICLE · INSTALLATION

How to install an eSIM in two minutes

A step-by-step guide to installing an eSIM: what you need first, the actual install steps, and how to confirm it worked before you travel.

3 MIN READ · FEB 2026

Japan for the first time: a week that says it wellJP

GUIDE · ASIA

Japan for the first time: a week that says it well

A first-timer's Japan itinerary built on restraint: three unhurried days in Tokyo, three in Kyoto, and a final day left open for Nara, Osaka or Kamakura.

12 MIN READSee JP plans →

OFFER · SUMMER IN EUROPE

One plan, thirty countries, zero roaming sonnets of regret.

Regional Europe eSIM. Install once, hop borders freely.

Browse Europe plans

Latest lessons

eSIM education · 30 topics →
The travel-day checklist

Nº 30 · CHECKLISTS

The travel-day checklist

6 MIN →
After the trip: should you delete your eSIM?

Nº 29 · INSTALLATION

After the trip: should you delete your eSIM?

4 MIN →
eSIM for tablets and smartwatches

Nº 28 · DEVICES

eSIM for tablets and smartwatches

5 MIN →
Unlocked vs carrier-locked phones

Nº 27 · DEVICES

Unlocked vs carrier-locked phones

5 MIN →
Battery myths, tested

Nº 26 · DEVICES

Battery myths, tested

5 MIN → All 30 lessons →

Tool

Will thy phone take an eSIM?

Two questions, a plain answer.

Check my phone

The postcard · monthly

One letter a month. No spam, only stanzas.

Guides by destination

30 destinations · All guides →
Vietnam by scooter and street stall
VN
California, honestly, and only California
US
Bergen to Oslo, the honest cost of the view
NO

All guides

30 destinations →

The complete index

30 lessons · 30 destinations · 3 tools

I. The education syllabus

Nº 01What is an eSIM? A plain-language guideWhat is an eSIM? A plain-language guideNº 02eSIM vs physical SIM: what actually changeseSIM vs physical SIM: what actually changesNº 03Is your phone eSIM compatible? The full listIs your phone eSIM compatible? The full listNº 04How to install an eSIM in two minutesHow to install an eSIM in two minutesNº 05Activate before you fly: the pre-flight ritualActivate before you fly: the pre-flight ritualNº 06Data roaming explained (and why it costs so much)Data roaming explained (and why it costs so much)Nº 07How much data do you need for a week abroad?How much data do you need for a week abroad?Nº 08Keep your number, carry our dataKeep your number, carry our dataNº 09Dual SIM done right: home line plus travel dataDual SIM done right: home line plus travel dataNº 10What happens when your plan runs outWhat happens when your plan runs outNº 11Topping up abroad without tearsTopping up abroad without tearsNº 12eSIM on iPhone: step by stepeSIM on iPhone: step by stepNº 13eSIM on Android: step by stepeSIM on Android: step by stepNº 14QR code vs one-tap installQR code vs one-tap installNº 15APN settings, demystifiedAPN settings, demystified
Nº 16Why your eSIM shows "No service" (and how to fix it)Why your eSIM shows "No service" (and how to fix it)Nº 17Hotspots and tethering on a travel eSIMHotspots and tethering on a travel eSIMNº 18eSIM security: is it safer than plastic?eSIM security: is it safer than plastic?Nº 19WhatsApp, iMessage and your eSIMWhatsApp, iMessage and your eSIMNº 20Country vs regional vs global plansCountry vs regional vs global plansNº 21Two countries, one trip, one eSIMTwo countries, one trip, one eSIMNº 22eSIM on cruises and ferrieseSIM on cruises and ferriesNº 23In-flight data: myths at 30,000 feetIn-flight data: myths at 30,000 feetNº 24Business travel: receipts, VAT and expensesBusiness travel: receipts, VAT and expensesNº 25How eSIMs actually work: the tech behind the tapHow eSIMs actually work: the tech behind the tapNº 26Battery myths, testedBattery myths, testedNº 27Unlocked vs carrier-locked phonesUnlocked vs carrier-locked phonesNº 28eSIM for tablets and smartwatcheseSIM for tablets and smartwatchesNº 29After the trip: should you delete your eSIM?After the trip: should you delete your eSIM?Nº 30The travel-day checklistThe travel-day checklist

II. Thirty destinations

Amsterdam by bike, and the day you leave it behindAmsterdam by bike, and the day you leave it behindBali beyond the beach clubs, then the GilisBali beyond the beach clubs, then the GilisBangkok, then north to the mountainsBangkok, then north to the mountainsBarcelona beyond the RamblasBarcelona beyond the RamblasBergen to Oslo, the honest cost of the viewBergen to Oslo, the honest cost of the viewBerlin, then the trains take overBerlin, then the trains take overCairo and the Nile, and how to haggle without the flinchCairo and the Nile, and how to haggle without the flinchCalifornia, honestly, and only CaliforniaCalifornia, honestly, and only CaliforniaChina, sorted before you landChina, sorted before you landCroatia's coast, one ferry at a timeCroatia's coast, one ferry at a timeDubai beyond the mallsDubai beyond the mallsGreece, island by islandGreece, island by island
All 30, A to Z →

III. Tools

eSIM compatibility checker→
Data calculator
Coverage map