What Is an eSIM? A Plain-English Guide for Canadian Travellers

If you've ever come home from a trip to a surprise $200 roaming bill, an eSIM is the thing that prevents that from happening again. It's not a new service or a separate device — it's already built into most phones made after 2018. Most Canadians just don't know it's there.

What Is an eSIM?

A traditional SIM card is a small physical chip you slot into your phone. It identifies you to a mobile network and lets you make calls, send texts, and use data. When you travel, your Canadian SIM connects to a foreign network through a roaming agreement — and your carrier charges you for every day that happens.

An eSIM (embedded SIM) does the same job, but it's built directly into your phone's circuitry. There's no chip to insert or swap. Instead, you download a carrier profile digitally — the whole process takes a few minutes from your phone — and your device connects to a local network at your destination as if you'd bought a local SIM card.

The practical difference: instead of paying Rogers or Bell $16/day to roam in the US, you pay roughly $35 CAD for a 10GB eSIM plan purchased directly on Cellulo that covers your entire trip.

Is My Phone eSIM-Compatible?

Most flagship phones manufactured since 2018 support eSIM. This includes:

iPhone XS and later (all models)
Samsung Galaxy S20 and later
Google Pixel 4 and later
Most recent flagship Android devices

One important requirement: your phone must be carrier-unlocked. If you bought your phone directly from a carrier in Canada and haven't unlocked it, it may only work with that carrier's SIMs — including eSIMs. Canadian carriers are legally required to unlock devices on request, often at no charge after a short period. Check your carrier's website or call them before your trip.

Not sure if your specific model is compatible? Check your phone's Settings — look for "Cellular" or "Mobile Data" and see if there's an option to add a plan or eSIM.

How Does an eSIM Work in Practice?

The process from purchase to connected is straightforward:

Buy an eSIM plan for your destination on Cellulo — takes about two minutes
Install the eSIM profile on your phone before you leave home (you need a Wi-Fi or data connection to download it)
At your destination, switch your active line to the eSIM
Your phone connects to the local network — no SIM tray, no airport kiosk, no hunting for a convenience store

One thing worth doing before you leave: install the eSIM at home on Wi-Fi rather than scrambling at the airport. See the section below on your Canadian number for the other important step before you take off.

Can I Keep My Canadian Number When Using an eSIM?

This is the most common question we hear — and the answer requires a bit of explanation.

Your Canadian number stays on your physical SIM. When you're abroad and using an eSIM for local data, your Canadian number is technically still active unless you turn it off. That's where the problem starts.

Even if you turn off data roaming on your Canadian line, your carrier can still charge a daily roaming fee just for your phone being reachable on that number — receiving a text, a missed call, or even a network ping is enough to trigger it. Rogers, Bell, and Telus all have daily roaming passes that activate the moment your phone touches a foreign tower, whether you intended to use it or not.

Cellulo's advice: turn your Canadian SIM line off completely before you take off.

Go to your phone's settings, find your Canadian line, and disable it entirely — not just data roaming, but the line itself. This guarantees zero roaming charges from your Canadian carrier for the duration of your trip.

For calls and messages, use data-based apps instead: WhatsApp, iMessage, and FaceTime all work over your eSIM data connection and will reach people on your Canadian number as long as you registered them before leaving home. Most travellers find this works seamlessly — the people you're calling don't notice any difference.

When you return to Canada, re-enable your Canadian line and your number is right where you left it.

What Does an eSIM Actually Cost?

Prices vary by destination and data amount, but here's a realistic picture of what travel eSIMs cost on Cellulo:

USA (10GB / 30 days): approximately $35
Europe Regional (10GB / 30 days): approximately $50
Japan (10GB / 30 days): approximately $19
Mexico (10GB / 30 days): approximately $16

Compare that to Canadian carrier roaming rates: $12–$16/day in the US, $15–$18/day internationally. A 10-day US trip costs $140 per person through your carrier. The same trip on an eSIM runs about $35. For a family of four, that's $420 back in your pocket.

eSIM vs. Your Canadian Plan's Roaming Add-On

Some Canadian plans include roaming as an add-on or advertise "unlimited" international data. The fine print matters. Most throttle speeds to 2G or 3G — effectively unusable for maps or anything that requires a real connection — after 500MB to 1GB of use per day.

An eSIM gives you a defined data bucket at full local network speeds — 4G or 5G depending on the destination — until it runs out. No daily resets, no speed caps, no midnight billing surprises.

When an eSIM Makes Sense — and When It Doesn't

An eSIM is the right choice for almost any trip longer than a day or two where data is a priority — navigation, maps, booking, sharing photos in real time.

The one scenario where your Canadian carrier roaming pass still makes sense: short border crossings where you need to receive calls and texts on your Canadian number and aren't doing much data-heavy activity. For a two-hour drive into the US and back, paying $14 for the convenience of keeping your number active is reasonable.

For anything longer, the math doesn't support carrier roaming.

A Few Things to Know Before You Buy

Not all eSIM plans are equal. A few things worth checking before purchasing:

Top-up availability — some plans let you add more data if you run out; others require purchasing a new eSIM entirely
Calls and texts — most travel eSIMs are data-only; calls and texts still go through your Canadian number if your primary SIM is active, or through apps like WhatsApp if it isn't
QR codes are single-use — if you delete an eSIM from your phone, you usually cannot reinstall it. Contact Cellulo support rather than deleting if you run into connection issues
Multiple eSIMs — most modern phones can store several eSIM profiles, which is useful for frequent travellers who visit multiple destinations

Browse travel eSIM plans by destination on Cellulo — you can purchase and install your plan in minutes, before you leave home.