SIM card
Enable an agent to recognise a SIM card, assess its subscription and access state, and determine which installation, authentication, transfer or retirement actions are appropriate.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
recalled by Codex without web access - no source was read
Researched by: Codex
Purpose and description
Enable an agent to recognise a SIM card, assess its subscription and access state, and determine which installation, authentication, transfer or retirement actions are appropriate.
A SIM card is a secure integrated-circuit card used in cellular equipment to hold subscriber identity data and authentication credentials and perform authentication functions, traditionally through a SIM application and, in modern networks, commonly through a USIM application on a UICC.
It can be Identify and match a card to an authorised inventory or subscription record using permitted identifiers.; Assess whether a card can be installed in a specified device and slot.; Support authorised PIN verification or operator-directed unblocking without exposing credentials.; Diagnose whether failure concerns card detection, application access, subscription state or network registration.; Coordinate authorised activation, suspension or replacement through the responsible operator.; Prepare a card for reassignment or retirement by checking service revocation and treatment of any locally stored data..
Distinguishing features
Provides or hosts a mobile subscriber-identity application used in network authentication; physical resemblance to a memory card is insufficient.
A UICC is the secure carrier, while SIM and USIM identify applications; a card may host multiple applications and should not be classified solely by its packaging.
A card identifier such as ICCID identifies a different object from the subscriber identity, telephone number or handset IMEI.
A removable SIM card can be moved between compatible devices, whereas a downloadable eSIM profile is installed on an eUICC and is not itself a removable card.
Presence of an intact card does not establish an active subscription, an unlocked application or permission to use the associated service.
Scope
+ Identification of the card, its carrier technology and resident SIM or USIM applications
+ Physical format, interface and compatibility with a target device
+ Relationships between card identifiers, subscriber identities and operator subscriptions
+ Authentication capabilities, credential protection and PIN or PUK access state
+ Provisioning, activation, replacement, loss and retirement states
- Handset hardware, operating system and device identity management
- Mobile network infrastructure and radio coverage
- Tariff pricing, billing and the full mobile service contract
- The subscriber's complete personal identity record
- General-purpose smart cards without a mobile subscriber-identity application
- Detailed eSIM provisioning infrastructure and profile-package management
Characteristics
- Carrier and application classification
- Legacy SIM card; UICC hosting SIM, USIM or other identified applications; eUICC relationship; unknown Prevents conflating the secure carrier with its applications and determines which compatibility questions apply.
- Physical format
- Full-size; mini-SIM; micro-SIM; nano-SIM; embedded package; other; unknown Determines mechanical fit and whether the record concerns a removable card or an embedded implementation.
- Target-device compatibility
- Target device and slot linked to confirmed, incompatible or unverified compatibility Mechanical fit alone does not establish application, interface or operator compatibility.
- Card identifier
- ICCID where available, with observation source and masked display Supports card inventory and replacement tracking without treating the identifier as proof of service ownership.
- Subscription association
- Operator subscription linked to subscriber identities and assigned telephone numbers where applicable Keeps card identity separate from subscriber identity and potentially changing number assignments.
- PIN access state
- Verification not required; verification required; verified for current session; blocked; unknown Determines whether application use can proceed and avoids unsafe repeated PIN attempts.
- Remaining verification attempts
- Non-negative integer attempts, separately for each reported PIN or unblock credential; unknown if unreported Indicates the risk of further verification attempts without assuming a universal retry limit.
- Operator service state
- Unprovisioned; pending activation; active; suspended; deactivated; unknown, using operator-confirmed meanings Separates service authorisation from local card readability and PIN status.
- Custody and use authority
- Issuer, subscription holder, current custodian and authorised operator, with evidence Physical possession alone does not authorise activation, replacement or access to stored data.
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 5 bundles · 9 layers · 17 findings · 25 questions.
Carrier and application boundary Establishes which physical medium and subscriber-identity applications the record represents.
SIM terminology commonly conflates a card, a UICC, a USIM application and an eSIM profile, leading to incorrect installation or transfer decisions.
Represented SIM object
Identifies the object behind the registry label and its relationship to embedded implementations.
Carrier and application separation
Record the carrier and its identified applications separately; flag unresolved use of the term SIM instead of inferring application type from appearance.
- Does this record represent a legacy SIM card, a UICC hosting subscriber applications, or an embedded implementation? definition
- If an eSIM profile is involved, which object is the carrier and which object is the downloadable profile? boundary
Device installation fit
Connects card format and application support to a concrete target device.
Slot and application compatibility
Assess mechanical fit, interface support and required subscriber application independently, using evidence for the target device.
- What physical format does the card have, and does the target slot accept it directly or require an approved adapter? measurement
- Which resident application and interface capabilities does the target device require, and what evidence confirms support? boundary
Subscriber identity and issuance Relates the card to its issuer, subscriber identities and operator service records.
Card identifiers, subscriber identities and telephone numbers serve different purposes and can change through different processes.
Identifier associations
Maintains the distinctions and evidence behind card-to-subscription mappings.
Card, subscriber and number mapping
Record permitted identifiers and their associations without assuming a telephone number is present on the card, current or unique to it.
- Which ICCID and subscriber identities are confirmed, and were they obtained from the card, packaging or an operator record? provenance
- Which subscription and telephone-number assignments are current, and what establishes their association with this card? provenance
Issuer and custody
Separates operator issuance, subscription authority and physical possession.
Authorised card control
Identify the responsible issuer or service provider and the parties entitled to use, recover or replace the card.
- Who issued the card and who currently administers its associated mobile subscription? provenance
- What evidence authorises the current custodian or agent to activate, unblock, suspend or replace it? action
Authentication and local access Describes authentication capability, protected credentials and local verification barriers.
A SIM is a security-bearing medium; authentication capability must be understood without turning the model into a store of secret credentials.
Network authentication capability
Records the supported subscriber-authentication role and its operational evidence.
Protected authentication operation
Record supported authentication applications and observed results while excluding secret key material from the model.
- Which subscriber-authentication application is available, and which network or device requirements must it satisfy? definition
- What authorised diagnostic evidence distinguishes authentication failure from failure to detect or access the card? measurement
PIN and unblocking state
Tracks local access restrictions and safe recovery options.
Verification and retry budget
Record which verification control applies, its reported state and remaining attempts; distinguish card PIN restrictions from handset or operator locks.
- Which PIN or unblock control is involved, and how many attempts remain according to the device or authorised card interface? measurement
- Is another verification attempt justified, or must the authorised holder obtain operator recovery assistance or a replacement? action
Service lifecycle and retirement Connects provisioning and observed usability to replacement, loss handling and end of use.
A readable card can be inactive, a replacement can invalidate its predecessor, and physical disposal alone does not establish service revocation.
Activation and service diagnosis
Separates card condition and access from operator authorisation and network availability.
Independent operational states
Record card detection, application access, operator service state and observed network registration as distinct observations with timestamps.
- Is the card detected and its application accessible, and what service state does the operator report? measurement
- What evidence attributes the current failure to the card, device restrictions, subscription authorisation or network conditions? boundary
Replacement and end of use
Controls continuity of service and disposition of the previous card and its data.
Replacement, revocation and data disposition
Track the operator-confirmed relationship between old and replacement cards, service revocation and any card-resident data requiring authorised treatment.
- When replacing or reporting this card lost, what confirms the old card's service status and the replacement card's subscription association? provenance
- Before reassignment or disposal, what card-resident contacts, messages or other accessible data require preservation or removal, and what confirms service revocation? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Check these first
Recalled without web access and unsourced; every item is a lead to verify.
- This is recalled knowledge; no sources were consulted.
- SIM is used colloquially for several distinct objects: the legacy application, a UICC carrying USIM, and an eSIM subscription profile.
- Check applicable standards editions, ICCID length conventions and operator-specific provisioning behavior before implementation.
- Which of these check these first hold for the sense of SIM card this model covers, and on what evidence? provenance
Kinds and varieties
Recalled without web access and unsourced; every item is a lead to verify.
- Full-size removable card (1FF)
- Mini-SIM (2FF)
- Micro-SIM (3FF)
- Nano-SIM (4FF)
- Embedded eUICC supporting downloadable subscription profiles, commonly called eSIM
- Which of these kinds and varieties hold for the sense of SIM card this model covers, and on what evidence? provenance
Identifiers and schemes
Recalled without web access and unsourced; every item is a lead to verify.
- ICCID - ITU-T E.118 - Decimal identifier beginning with 89 for telecommunications - Identifies the card or subscription profile; distinct from the subscriber identity and telephone number.
- IMSI - ITU-T E.212 - Up to 15 decimal digits comprising MCC, MNC and MSIN - Identifies a mobile subscription; the mobile country code has three digits and the mobile network code has two or three.
- EID - GSMA eUICC identification - 32 decimal digits - Identifies an eUICC, which can contain multiple subscription profiles.
- Which of these identifiers and schemes hold for the sense of SIM card this model covers, and on what evidence? provenance
Standards and regulation
Recalled without web access and unsourced; every item is a lead to verify.
- ETSI TS 102 221 specifies the UICC-terminal interface, including physical and logical characteristics.
- 3GPP TS 51.011 specifies the SIM-mobile equipment interface for GSM.
- 3GPP TS 31.102 specifies characteristics of the USIM application.
- ISO/IEC 7816 series, issued by ISO and IEC, standardizes integrated-circuit cards and their interfaces.
- GSMA SGP.22 specifies remote SIM provisioning for consumer devices.
- Which of these standards and regulation hold for the sense of SIM card this model covers, and on what evidence? provenance
Real-world use
Recalled without web access and unsourced; every item is a lead to verify.
- Authenticating mobile subscriptions for voice, messaging and data services.
- Moving a subscription between compatible devices by transferring a removable card.
- Provisioning and changing subscriptions remotely on eSIM-capable devices.
- Providing subscription credentials for cellular meters, trackers, vehicles and other connected equipment.
- Storing limited contacts and SMS messages on implementations that support these functions.
- Which of these real-world use hold for the sense of SIM card this model covers, and on what evidence? provenance
Typical measurements
Recalled without web access and unsourced; every item is a lead to verify.
- Mini-SIM (2FF) nominal length × width × thickness - 25 × 15 × 0.76 - mm
- Micro-SIM (3FF) nominal length × width × thickness - 15 × 12 × 0.76 - mm
- Nano-SIM (4FF) nominal length × width × thickness - 12.3 × 8.8 × 0.67 - mm
- Which of these typical measurements hold for the sense of SIM card this model covers, and on what evidence? provenance
Failure modes and hazards
Recalled without web access and unsourced; every item is a lead to verify.
- Damaged, contaminated or poorly seated contacts can prevent the device from detecting a removable card.
- Repeated incorrect PIN attempts can block access and require a PUK; exhausting PUK attempts can permanently block the affected application.
- Fraudulent SIM replacement or subscription transfer can redirect calls and messages and compromise SMS-based account recovery.
- Lost or stolen cards can enable unauthorized subscription use when access controls are insufficient.
- Deleted, disabled or unsuccessfully provisioned eSIM profiles can interrupt service until a usable profile is restored or installed.
- Which of these failure modes and hazards hold for the sense of SIM card this model covers, and on what evidence? provenance
Regional variation
Recalled without web access and unsourced; every item is a lead to verify.
- Subscriber registration and identity-verification requirements vary by jurisdiction.
- Availability of eSIM activation, profile transfer and remote provisioning varies by operator and market.
- Roaming availability and charges depend on operator agreements and applicable regional rules.
- Which of these regional variation hold for the sense of SIM card this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Recalled without web access and unsourced; every item is a lead to verify.
- UICC - The UICC is the secure card platform; SIM and USIM are applications that can run on it.
- USIM - USIM is a subscriber identity application used for UMTS and later cellular systems, rather than a physical card size.
- eSIM - Commonly denotes an eUICC and remotely provisioned subscription profiles; it does not simply mean a smaller removable SIM card.
- Memory card - A memory card primarily provides general-purpose data storage; a SIM card primarily protects subscription credentials and performs controlled authentication operations.
- IMEI - IMEI identifies mobile equipment, whereas SIM-associated identifiers identify a card, profile or subscription.
- Telephone number - A telephone number is a service addressing identifier assigned to a subscription; it is distinct from the SIM's ICCID and IMSI.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of SIM card this model covers, and on what evidence? provenance
What the second pass must settle
- Does the authoritative registry intend SIM card to include embedded UICCs and eSIM profiles, or should those remain linked neighbouring concepts?
- Which primary specifications should ground the distinctions among legacy SIM cards, UICC carriers, SIM applications and USIM applications?
- Which operator and device interfaces can reliably expose activation state, verification retry counts and replacement status without collecting secret credentials?
- How should multi-application cards and cards supporting multiple subscriber identities be represented without assuming one card equals one subscription?
- Which card-resident data and retirement procedures apply across the supported card generations and issuers?