The most persistent eSIM myths are wrong on the facts. An eSIM does not replace your phone number, does not need Wi-Fi to work once installed, is not less secure than a physical SIM, and is not limited to data only, because some providers include calls and a real number. Below we debunk the seven myths that still cause travellers to overpay or avoid eSIMs needlessly.

eSIMs have been mainstream for years, yet the same misunderstandings keep circulating and cost travellers money or confidence. Here are the seven we hear most, each with the myth and the reality.

Myth 1: “An eSIM replaces my phone number”

Myth: Activating a travel eSIM will overwrite or cancel my normal number.

Reality: A travel eSIM is an extra line, not a replacement. On a dual-SIM phone your home SIM and number stay active alongside the eSIM. You keep your usual number for calls and texts, and use the eSIM for data. You only lose your old number if you deliberately port or cancel it. See what actually happens to your number and data.

Myth 2: “You need Wi-Fi for an eSIM to work”

Myth: An eSIM only works where there is Wi-Fi.

Reality: You need the internet only once, to download the eSIM profile, which is why you install it before you fly. After that it connects to mobile networks by itself, exactly like a physical SIM, with no Wi-Fi required. This is also why you should set up at home rather than at the airport.

Myth 3: “eSIMs are less secure”

Myth: A digital SIM is easier to hack than a plastic one.

Reality: eSIMs are at least as secure as physical SIMs, and arguably more so. Because the eSIM is embedded in a tamper-resistant chip, it cannot be physically removed and swapped by a thief, which removes one common SIM-theft tactic. We cover this in full. Is an eSIM safe?

Myth 4: “You can only have one eSIM”

Myth: One eSIM per phone, then you are full.

Reality: Most eSIM phones store multiple profiles, often eight or more, and let you switch between them in settings. Usually one or two can be active at once alongside a physical SIM. So you can keep separate eSIMs for different countries on the same handset and choose which one is live.

Myth 5: “eSIMs are only for data, never calls”

Myth: You cannot make a normal phone call on an eSIM.

Reality: This is true of most travel eSIM brands, but it is a product choice, not a technology limit. Many providers sell data-only eSIMs, but some, including WorldSIM, offer eSIMs with voice calls, SMS and a real UK and USA number. Full detail in can you make normal phone calls on an eSIM.

How eSIMs compare to standard networks on price

That data-only myth persists partly because most travel eSIMs really are data-only so when a plan does include voice and text, it’s worth seeing what that actually costs against the alternative of just roaming on your home network. Here’s WorldSIM eSIM Pro against standard UK PAYG rates abroad:

The table below highlights the key differences between WorldSIM eSIM Pro and popular  mobile providers.

Provider	Price	Voice	SMS	Data	Coverage
WorldSIM eSIM Pro	£25	£0.04/min incoming, £0.34/min outgoing	£0.15 per message	10GB–85GB bundles (£5–30/GB)	All 195+ countries
EE	£9 PAYG	£1.20/min	£0.93	Separate roaming pass	Incoming only
Vodafone	£10 PAYG	£0.60/min	£0.08	£0.12/MB (2GB–4GB bundles: £17–27)	Incoming only
Lyca	£10 PAYG	£0.80/min	£0.48	3GB–7GB bundles: £10–20	Incoming only
Three	£10 PAYG	£0.35/min	£0.15	£0.10/MB (6GB inclusive)	Incoming only

Myth 6: “Setting up an eSIM is complicated”

Myth: You need to be tech-savvy to install one.

Reality: Setup is usually scan a QR code, tap confirm, done. You receive the code by email, scan it on home Wi-Fi, label the line, and switch it on when you land. It typically takes a couple of minutes. If anything does go wrong, our eSIM fix checklist resolves most issues.

Myth 7: “eSIMs have worse coverage than local SIMs”

Myth: A travel eSIM gives a weaker signal than a local SIM.

Reality: A travel eSIM runs on the same local partner networks a local SIM would use, so coverage is comparable. The difference is convenience: the eSIM connects automatically on arrival and across borders, with no shop visit and no new number. If signal ever drops, it is usually a settings issue, covered in eSIM installed but no signal abroad.

The myth	The reality
Replaces your number	Adds a line; your number stays via dual SIM
Needs Wi-Fi to work	Only to install; then works on mobile networks
Less secure	As secure or more; cannot be physically stolen
One eSIM per phone	Stores many profiles; switch in settings
Data only	Some plans include calls and a number
Hard to set up	Scan a QR code; about two minutes
Worse coverage	Uses the same local networks

Try an eSIM that breaks the data-only myth. WorldSIM eSIMs work across 100+ countries with no roaming charges, and unlike most providers, you can choose a plan with calls, SMS and your own UK and USA number. Explore eSIM plans

Key takeaways

• An eSIM adds a line; it does not replace your number
• Wi-Fi is needed only to install, not to use
• eSIMs are as secure as, or more secure than, physical SIMs
• Phones hold multiple eSIM profiles you can switch between
• Some eSIMs do include calls and a real number

Frequently asked questions

Q: Does an eSIM replace my phone number?
A: No. A travel eSIM is an additional line. On a dual-SIM phone your existing SIM and number stay active alongside it, so you keep your usual number for calls and texts while the eSIM handles data. You only lose your old number if you actively port or cancel it.

Q: Do you need Wi-Fi to use an eSIM?
A: Only to install or download the profile, which is why you set it up before you travel. Once installed, the eSIM connects to mobile networks on its own and needs no Wi-Fi, exactly like a physical SIM.

Q: Are eSIMs less secure than physical SIMs?
A: No. eSIMs are at least as secure and in some ways more so. Being embedded in the phone, an eSIM cannot be physically removed and swapped by a thief, and the data sits in a tamper-resistant chip.

Q: Can you only have one eSIM on a phone?
A: No. Most eSIM phones store multiple profiles, often eight or more, and switch between them in settings, though usually only one or two are active at once alongside a physical SIM. You can keep eSIMs for different countries on the same phone.

Q: Do eSIMs only offer data and not calls?
A: That is true of most travel eSIM brands but not all. Many sell data-only eSIMs, but some, including WorldSIM, offer eSIMs with voice calls, SMS and a real phone number. The limitation is a product choice, not the technology.

Q: Can a WorldSIM eSIM Pro receive OTPs from banks and government sites?
Yes. WorldSIM’s eSIM Pro is SMS-enabled and receives one-time passwords from UK banks (Barclays, Monzo, HSBC), HMRC, PayPal, Apple, and Google in 195+ countries, just like a physical SIM.