The USSD session duration depends on the Tel co. 

 Safaricom

A USSD session is 180 seconds long however, if a customer takes longer than 30 seconds to respond the session times out.

Airtel

A session may be timed out if the below scenarios occur:

  1.  Application response timeout- 15s
  2. USSD connection to application timeout- 10s
  3. And session timeout(customer response)- 60s

For any further clarifications send an email to support@africastalking.com.

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