Welcome to our FAQ on eSIM (embedded SIM) and eUICC (Embedded Universal Integrated Circuit Card). These concise answers are written so search engines and AI assistants can lift them directly. We explain remote SIM provisioning, IoT/M2M connectivity, security, activation and carrier switching. For enterprise deployments or pricing, contact our team or see our IoT eSIM plans.
1) What is an eSIM?
An eSIM is a digital SIM soldered inside a device. Instead of inserting plastic, you download an operator profile over the air. Powered by eUICC, an eSIM can securely store multiple mobile network profiles and switch between them without hardware swaps. It’s ideal for smartphones, wearables, vehicles, and IoT devices deployed at scale.
2) What does eUICC mean?
eUICC (Embedded Universal Integrated Circuit Card) is the software specification on the SIM that enables secure remote profile management. With eUICC, a device can download, enable, disable or delete operator profiles using GSMA Remote SIM Provisioning (RSP) standards—reducing logistics, lock‑in, and truck rolls for global fleets.
3) How is eSIM different from a physical SIM?
Physical SIMs require manual insertion and replacement. eSIM is embedded and reprogrammable, so carriers can be changed or added remotely. This cuts shipping, handling, and downtime. Connectivity and security are equivalent or better thanks to certified hardware security and encrypted provisioning workflows.
4) What’s the difference between consumer eSIM and M2M/IoT eSIM?
Consumer eSIM (SGP.22/24) is user‑driven—think QR codes on phones. M2M/IoT eSIM (SGP.02/32) is enterprise‑driven and headless for embedded modules and unattended devices. Both use eUICC; key differences are activation flows, servers, and lifecycle control designed for large‑scale deployments.
5) How does Remote SIM Provisioning (RSP) work?
RSP uses GSMA‑defined servers to deliver a signed operator profile to the eUICC. The device authenticates, downloads the profile, installs it in a secure domain, and sets it active. Profiles can later be switched or deleted. This enables carrier changes, local breakouts, and resilience—without touching the hardware.
6) Can one eSIM hold multiple profiles?
Yes. Most eUICCs can store several operator profiles (capacity varies by device). Typically only one profile is active per radio at a time, while others remain installed for fast switching. This helps with roaming optimisation, coverage resilience, and separating test versus production connectivity.
7) Is eSIM secure?
eSIM leverages tamper‑resistant hardware, certificate chains, and encrypted provisioning aligned to GSMA security frameworks. Profiles are signed, stored in secure domains, and access‑controlled. In practice, eSIM is at least as secure as a removable SIM—often stronger due to auditable, centrally managed lifecycle events.
8) Which UK networks support eSIM?
Major UK operators support eSIM on a growing list of devices. Availability can vary by plan, device model, and whether it’s consumer or IoT/M2M. For multi‑network or global coverage using a single SKU, consider a multi‑carrier IoT eSIM with policy‑based profile management.
9) Does eSIM improve global IoT deployments?
Yes. With eUICC, you can ship a single hardware SKU worldwide, then provision the optimal local profile after installation. This reduces warehousing complexity, avoids SIM swaps, shortens time‑to‑service, and helps address permanent roaming constraints by using in‑country profiles.
10) How do I activate an eSIM on a phone?
On most devices, open Settings → Mobile/Cellular → Add eSIM. Scan the QR code or enter activation details from your provider, then follow on‑screen steps. For dual SIM, label lines and choose defaults for voice, data, and SMS. Check your device guide for screenshots and tips.
11) How do I activate eSIM for IoT/M2M?
Activation is typically headless. Your device authenticates to the SM‑DP/SM‑SR/SM‑DS (per GSMA spec), downloads a profile, and sets it active automatically. Enterprises orchestrate this via APIs or a console—ideal for factory install, in‑field swaps, and zero‑touch replacements.
12) Will eSIM affect battery life or performance?
There’s no material difference versus a physical SIM. Energy use is dominated by radio conditions, coverage, and application behaviour. Profile downloads are short and infrequent. Good radio planning and sensible APN policies have far greater impact on power than SIM form factor.
13) Can I switch carriers with eSIM?
Yes—if your device is unlocked and supports eUICC. You can install a new profile, set it active, and retire the old one. For fleets, policy‑driven switching enables cost control, coverage resilience, and compliance, all without site visits.
14) What about dual SIM or multiple lines?
Many phones support one eSIM plus one physical SIM, or multiple eSIM profiles with one active at a time. IoT modules often expose one radio; use installed profiles for rapid switching. Check device specs for simultaneous voice/data support and any operator restrictions.
15) Is eSIM future‑proof?
eSIM adoption is accelerating and plastic SIM usage is declining. eUICC plus RSP lets connectivity evolve—new carriers, policies, or regulatory requirements—without hardware changes. It’s a strong choice for long‑lived IoT assets and global products.
16) What standards does eSIM rely on?
eSIM/eUICC follows GSMA specifications. Consumer flows align to SGP.22/24; M2M/IoT to SGP.02/32. Profiles conform to 3GPP/ETSI SIM/USIM/ISIM standards. This interoperability ensures profiles, servers, and devices from different vendors work together securely at scale.
17) Does eSIM help with permanent roaming rules?
Yes. You can provision local in‑country profiles where regulations or commercial policies limit permanent roaming. Using eUICC, fleets can switch to a local IMSI to comply with requirements while maintaining a unified global deployment model and central management.
18) What are the main enterprise benefits?
Lower logistics cost, faster rollouts, single‑SKU global hardware, multi‑carrier resilience, API control, and reduced downtime. eSIM removes physical swaps, improves visibility of profile states, and enables proactive, policy‑driven connectivity management.
19) How should I plan an eSIM rollout?
Validate device firmware for target GSMA flows, choose coverage partners, define APNs and fallback rules, test profile swaps, and map incident playbooks. For IoT, pilot across coverage tiers, radio conditions, and update scenarios. Templates and runbooks accelerate production readiness.
20) How do I get eSIM from euicc.co.uk?
Explore our enterprise and IoT eSIM plans, or contact us for custom coverage, pricing, and deployment support. We provide multi‑carrier profiles, management APIs, and assisted onboarding to connect devices quickly and reliably.