eSIM vs physical SIM: which is more private?

A common privacy claim is that eSIMs are more surveilled than physical SIMs because "the carrier can push updates directly to your device". This is technically true and largely irrelevant.

What actually differs

The subscriber identity (the IMSI) works identically on both. The device identity (the IMEI) is broadcast by your phone regardless of SIM type. Location tracking via tower connections is identical. Metadata (who you called, when, for how long, from where) is identical.

The only real difference: an eSIM profile is provisioned over the internet via SM-DP+, so the carrier's provisioning server sees an IP address at the moment of install. A physical SIM is provisioned in a factory, but you almost always activated it against a carrier system that recorded your IP anyway.

Where eSIM is genuinely more private

• No physical retail interaction. No cashier scanning your ID, no in-store camera. You install from a QR code you received via a browser tab.
• No serial number tied to you. Physical SIMs are shipped with an ICCID printed on the plastic; carriers know which batch went to which distributor. An eSIM ICCID is generated at provisioning time.
• Portable across devices. An anonymous eSIM you bought once can be re-installed on a new device without any store interaction.

Where physical SIM used to win

Cash-purchased prepaid SIMs from convenience stores were, historically, the gold standard of anonymous mobile. In most of Europe that door closed years ago - mandatory ID registration killed prepaid anonymity. In the US it's mixed. Anonymous eSIMs bought with crypto are the closest modern equivalent.

The IMEI and IMSI, disentangled

Two identifiers get conflated in most privacy debates. The IMEI is the device - a serial number burned into the phone at the factory, broadcast to every tower the device attaches to, and identical regardless of what SIM is inside it. The IMSI is the subscriber - a number that lives on the SIM (physical or embedded) and identifies the account to the carrier. Anonymity attaches to the IMSI: an anonymous eSIM issues an IMSI with no personal data behind it. The IMEI never becomes anonymous no matter what SIM you use, which is why serious operational security includes rotating the physical device (or at least not using the anonymous SIM on the phone that also carries your identified subscription).

The remote-provisioning boogeyman, examined

The strongest version of the "eSIMs are less private" argument is that the GSMA's SM-DP+ specification allows carriers to push profile updates over the air. That is real. What it enables in practice is: activating a new profile, updating carrier settings, or - in extreme cases - deleting a profile. It does not give the carrier extra surveillance powers they didn't already have via the underlying network. A physical SIM's carrier can equally push OTA updates via SMS since roughly 2001; nothing about eSIM makes surveillance qualitatively worse.

Where physical SIMs still win, honestly

One niche: transferring a subscription to someone else. A physical SIM can be handed over; an eSIM profile is typically locked to a device (or requires transfer flows the carrier controls). If you plan to sell or gift the SIM itself, physical is easier. For any other purpose - travel, second lines, privacy - eSIM is at least equivalent and usually better.

The practical recommendation

For a traveler who cares about privacy: anonymous eSIM as the data line, primary identified SIM as the voice/SMS/2FA line, both in the same device, VPN on the traffic layer, and coins that weren't KYC-purchased in your name. That stack gets you closer to the old cash-prepaid experience than any single-SIM approach.