Mobile number not reported for devices using OPTUS SIM cards: carrier-dependent SIM data availability

Android

Title: Mobile number missing for OPTUS SIM cards — carrier does not store MSISDN on SIM

When devices are provisioned with OPTUS SIM cards, the mobile number field in the Esper Console remains blank, even though identical devices using TELSTRA SIM cards report mobile numbers correctly.

Why this happens

Esper retrieves the mobile number (MSISDN) by reading a specific file on the SIM card called EF-MSISDN, using the standard Android telephony API. OPTUS does not program this file on their SIM cards, so there is no number for Esper to read. This is a carrier policy decision — TELSTRA SIM cards do include this data, which is why mobile numbers appear for TELSTRA-provisioned devices.

Confirm the issue is carrier-specific

Navigate to Devices & Groups → [Device Name] → Device Info and locate the Mobile Number field. Confirm it is blank.
Note the carrier shown in the same view to confirm the device is using an OPTUS SIM.
If a spare device is available, insert a TELSTRA SIM into the same device model and check whether the Mobile Number field populates. This rules out a device or Esper configuration issue and confirms the cause is OPTUS carrier policy.

Workarounds

Because OPTUS does not write MSISDN data to their SIM cards, Esper cannot retrieve it. Use one of the following approaches instead:

Obtain number-to-IMEI mappings from OPTUS: Contact OPTUS through your business account portal or fleet management tools to request a list of mobile numbers mapped to IMEIs. Export IMEI data from Esper via Reports, or use the Esper API endpoint GET /v0/enterprise/{enterprise_id}/device/ and match on the imei field to correlate the two datasets.
Store mobile numbers as custom device properties: Once you have the numbers from OPTUS, record them against each device in the Esper Console using custom tags or device properties. Navigate to Devices & Groups → [Device Name] → Device Info and add the number as a custom property so it is visible alongside other device details.
Switch to TELSTRA SIM cards: If mobile number visibility within the Esper Console is a hard requirement for your deployment, TELSTRA SIM cards store and expose MSISDN data and will report correctly without any additional steps.

Confirm with OPTUS whether your SIM SKU includes MSISDN data

If your business agreement with OPTUS is supposed to include mobile number provisioning on the SIM, contact OPTUS directly and ask them to confirm whether the EF-MSISDN field is programmed on your specific SIM card SKU. Different enterprise SIM tiers can vary in how they are provisioned.

Verify: After storing mobile numbers as custom device properties, navigate to Devices & Groups → [Device Name] → Device Info and confirm the number appears in the custom properties section. For TELSTRA SIM cards, the native Mobile Number field should populate automatically within 5 minutes of the device coming online.

If this doesn't resolve it

If mobile numbers are not appearing for TELSTRA SIM cards on the same device model, the issue may not be carrier-related. Before contacting Esper Support, collect the following:

The device model and Android version
The carrier shown in Devices & Groups → [Device Name] → Device Info
A screenshot of the blank Mobile Number field
Confirmation of whether the SIM reports correctly in the device's native Settings app under About Phone → SIM Status

Still need help?

If you're experiencing missing mobile number data for devices with OPTUS SIM cards, please submit a support ticket and include your device serial numbers, SIM carrier details, and screenshots of the affected device profiles.