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Telnyx SIMs and eSIMs provide programmable cellular connectivity for devices, managed entirely through the API after you get them. This page covers the SIM types, the resources you work with, the lifecycle states and their costs, and how multi-IMSI selects a network.

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SIM Types

All Telnyx SIMs are eUICC-enabled. Three form factors:

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Resource Model

Three core resources, all API-managed:
  • SIM Card — the connectivity entity. Has an ICCID, status, data settings, optional voice flag. Covers both physical SIMs and eSIMs (eSIMs are purchased via a separate endpoint but become the same SIM Card resource with an activation code for OTA provisioning). Everything starts here.
  • SIM Card Group — bulk management. Apply data limits, network preferences, and Private Wireless Gateway configs to all SIMs in a group at once.
  • Mobile Phone Number — optional. Created when you enable voice or messaging on a SIM. Controls call forwarding, caller ID, messaging profile.

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SIM Lifecycle

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Multi-IMSI

Every Telnyx SIM carries multiple IMSIs (Telnyx, Sparkle, BICs, T-Mobile, US Cellular). An on-SIM applet automatically selects the best IMSI per location — local network attachment instead of roaming, lower latency, better rates. Default is automatic selection. You can override to manual per-SIM or per-group via API if you need to pin a specific IMSI for regulatory or testing purposes.

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Pricing

Three cost components:

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Next Steps

SIM Cards

Order physical SIMs and eSIMs, and learn how they are shipped and activated.

Lifecycle

State machine, transitions, and what to know about managing SIM status.

SIM Card Groups

Apply data limits, allowed networks, and security settings to many SIMs at once.

Bulk Operations

Run one-time batch operations on an explicit list of SIM cards.