Articles on: eSIMs

How can I troubleshoot a “PDP Authentication Failure” error on iOS?

A "PDP Authentication Failure" error means the eSIM cannot authenticate with the local network. The most common cause is incorrect APN settings or Mobile Data Switching being enabled.


Step 1: Check APN settings


Incorrect APN settings are the most common cause of this error.


  1. Go to Settings > Cellular > tap your Stippl eSIM (Secondary)
  2. Tap Cellular Data Network (or APN Settings)
  3. Under Cellular Data, clear the APN, Username, and Password fields — leave them all blank
  4. Restart your device


If you don't see "Cellular Data Network," your carrier may lock APN settings. Try Step 5 below.


Step 2: Turn off Allow Mobile Data Switching


  1. Go to Settings > Cellular
  2. Find Allow Mobile Data Switching and toggle it OFF


This ensures your iPhone routes data only through your Stippl eSIM.


Step 3: Verify your data balance


  1. Open the Stippl app > eSIM
  2. Confirm your plan is still active and has remaining data


Step 4: Manually select a network


  1. Go to Settings > Cellular > tap your Stippl eSIM (Secondary)
  2. Tap Network Selection
  3. Toggle Automatic OFF
  4. Wait for available networks to load, then select one


Step 5: Reset network settings


Go to Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings


This clears saved Wi-Fi passwords and VPN configurations, then forces your device to re-establish the network connection from scratch.


Still not working? Contact Stippl support with the email address linked to your Stippl account and we'll investigate.

Updated on: 03/08/2026

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